I think this is my favorite chapter so far (even if the part between Dexter and Numbuh Two took a dozen drafts to get right). As always, feedback is loved beyond measure, and I hope you enjoy the latest chapter in this Fusion Fall Saga!

Time Until the End of the Earth: 4 days, 14 hours, 32 minutes

"This. Is. Awesome!"

"Can we at least pretend to focus on the mission at hand?" Dexter asked as he frowned, unimpressed by the other boy's antics.

"Come on Dex," Numbuh Two cajoled, "you can't really tell me that you never take this baby out for a spin."

"I can because I have not," Dexter replied flatly. "The Odin is not some kind of play park ride built simply for your juvenile entertainment. She is the embodiment of aviary technological advancements at their finest, and you would do well to respect that. Would you quit that?" he added tersely, scowling at the display readouts that indicated his ship's horizon line—and therefore the ship its self—was completing its eight barrel roll since take off.

"She's loving it!" Numbuh Two defended. If he wasn't so worried about maintaining his stoic appearance, Dexter would have rolled his eyes.

"And when, might I ask, did you gain the ability to commune psychically with aircraft?"

A bright "Whoo-hoo!" was Numbuh Two's response, as the Odin began its ninth roll.

Biting back an annoyed growl, Dexter instead closed his eyes and let out a slow, steady breath, earning himself bemused looks from the technicians coordinating the rest of Earth's airborne forces. Ignoring the looks, Dexter addressed the holocube floating before him.

"Computress, activate control override for the Odin and level out."

"Aww," Numbuh Two whined as the displays showed the Odin's wild flight smoothing out. Dexter allowed himself a small smirk as he pictured Numbuh Two, the KND pouting as he stared down at displays all flashing the same message—Override Autopilot Engaged.

"Now that we've had our fun, can we focus on the mission?" Dexter asked.

"Has anyone ever told you you're a total stick in the mud?" Numbuh Two asked. Dexter raised an eyebrow.

"Yes, actually," he said. "Benjamin Tennyson." He frowned, and then added, "He wanted to 'borrow' my experimental hover-board and take it to a skate park."

There was a moment of silence from the Odin.

"Ben is officially my hero," Numbuh Two breathed, admiration dripping from his words. "And not just because of the whole alien thing. Although that is pretty cool too."

"Can we please focus?" Dexter asked, massaging his forehead with a gloved hand. "I would like to find out what Fuse is planning, preferably before he does it."

"You worry too much, you know that?" Numbuh Two asked, earning a scowl from the scientist.

"How much longer until you're at Pokey Oaks?" he snapped.

"ETA three minutes. I should have a visual soon enough."

Numbuh Two's response earned Dexter a handful of curious looks from the tower crew. They were all working with one ear directed towards the redhead, hoping to pick up any hint as to what the imperious scientist was doing blustering about their control tower.

Twenty minutes ago, Dexter had marched into the Sector V control tower—base of operations for all of the war's aviary forces—and announced that the runway needed to be cleared for a priority one aircraft launch. Confusion had reigned for a few moments, until one of the controllers recovered from Dexter's brash entrance enough to inform him that such action required authorization from Numbuh Two—only to be left all the more baffled when Numbuh Two, via holocube transmission, informed the tower that he himself was the one requesting take off.

From that point on the tower crew had done the equivalent of throwing their hands up in the air, shepherding Dexter over to one of their computers and leaving him to do his thing in peace.

His thing happening to be argue with Numbuh Two via holocube, while using the computer he'd been given to keep an eye on his precious stealth craft (leaving the tower crew muttering among themselves about haughty scientists and commandeering desk space).

Frowning darkly, Dexter scowled at the crew members looking his way until they'd all decided that had better things to do then gawk at him. Sighing he turned back to his holocube, and the excitable pilot on its other end.

"Just let me know when you get there."

"Professor, do you mind if I ask where you're taking us?" Gwen asked.

"You'll see soon enough," Professor Utonium assured her. "Just a little further."

For Gwen that idea that there was even a "little further" that they could go was surprising. At the Professor's request she, along with Numbuh One, Mandy, and Mac, had followed the scientist across Hero's Square to the towering Dexlabs facility from which a vast majority of the weaponry being used against Fuse came from, along with a number of highly advanced airships and communications devices. Once inside they'd spent a little time moving through passages and hallways of increasing levels of restricted security access.

And then they'd started moving down. For a good half an hour they'd navigated their way through a maze of hallways, elevators, locked doors, and stairwells. Gwen had lost track of their route somewhere around the third floor, and they'd dropped at least two dozen levels since then.

"How far down does this lab go?" Numbuh One had asked at one point as they climbed into yet another elevator. The Professor, sliding his ID card to access the elevator's panel of buttons, had shrugged.

"I've been as low as the hundred and eighth floor, but I'm pretty sure Dexter has personal labs even lower than those."

As they stepped through their latest multi-security-feature door Gwen wondered if maybe it was Dexter's personal labs they were heading for. As the thought crossed her mind they entered a hallway flanked by doors, some of which were crisscrossed with yellow caution tape and guarded by an array of retinal scanners, fingerprint pads, and what even looked like an advanced version of the K.N.D.'s booger identifier.

Atop it all were handmade signs, written in Dexter's blocky print, that boldly proclaimed "Restricted Access," "Unauthorized Personnel Not Permitted," and "No Deedee's!"

But it was a pair of heavy duty steel doors beyond these that the Professor headed for. Unlike the other doors, only a single, solitary card reader, placed at the center of the two doors, protected this passageway.

"This doesn't look very secure," Mac said, glancing back at the doors behind them as he spoke.

"It doesn't look that way, does it?" the Professor agreed. "But if someone who didn't have access through his door tried to open it in anyway the doors would lock down with five reinforced locking systems, and everything beyond these doors would be destroyed in a self destruct sequence. Your friend, Mr. Levin, helped us design the system," he added, looking at Gwen.

"Really?" she said, looking at the card reader with renewed interest. She knew Kevin's access around the lab had been recently upgraded, but she thought he'd simply been teasing her when he claimed he was now working on "super, top classified projects that only like, three other people really know about."

"Can I ask what would need such high tech security?" Numbuh One asked. The Professor hesitated and sighed.

"Before I show you what's behind these doors, there's a little back-story I need to give you first."

"What kind of back-story?" Gwen asked.

"The kind that very few know about," the Professor said. "You see, Fuse coming wasn't only being tracked by the K.N.D. bases out in space. The Plumbers and, to a lesser degree, Providence, were all aware of Lord Fuse to some extent once he'd entered our Solar System. They knew he was headed here for Earth, and that if we wanted to defend ourselves we were going to need all the help we could get.

"But this wasn't the first time the Plumbers had encountered Fuse. They'd heard stories from distant alien races about what Fuse was capable of. They knew that there was a chance that, even with our greatest heroes united, we might not be able to stop Fuse completely. So they created a backup plan, so to speak."

"What kind of backup plan?" Numbuh One asked.

"You mean like some kind of alien weapon?" Mandy added.

"Not exactly," the Professor said. "They knew that there was a chance they wouldn't be able to come up with something to stop Fuse completely. But they weren't willing to let the human race perish because of him. Even if they could only save some, it was better than none."

"You're talking about some kind of escape vessel," Gwen said, eyes widening.

"Exactly," the Professor said. "It was mostly being developed on a theoretical level, but soon after the first fusion goo broke the atmosphere the Plumbers contacted Dexter and, together with Providence scientists and technicians, they started work on the largest space vessel ever constructed."

"How large is it?" Mandy asked, "large enough to get an entire army off of Earth?"

"It can hold over seven hundred and fifty thousand people at max capacity," the Professor said. Four pairs of eyes gawked up at him.

"How did you manage to keep this a secret?" Gwen asked.

"Not many people knew about it, for starters," the Professor said. "And those that did...well, let's just say they're experts at hidden information."

"And is this ship what we're on our way to see?" Numbuh One asked. The Professor nodded.

"It's on the other side of this door."

"How complete is it?" Gwen asked. She didn't have to ask why they were being shown the ship, that much was obvious. If the Professor didn't think an evacuation of the Earth was necessary then he wouldn't be flaunting the super secret tools with which it could be done.

"Complete," the Professor said. "We could load it up and leave right now if we needed to. It's already been loaded with enough supplies to carry a full load of people to the nearest Plumber friendly planet system."

The silence that echoed after the Professor's words was deafening. Eventually Gwen broke it, her voice a whisper as she asked,

"Can we see it?" The Professor nodded, turning to the double doors with his ID badge in hand. He slid it through the innocuous reader, which beeped and flashed before a small light on the top turned green. A moment later and the impressive bang of a series of heavy duty locking mechanisms opening echoed in the hall.

"Everyone," the Professor said as he leaned forward, pushing the doors apart, "I'd like you all to meet the largest interstellar vessel ever built—the Skidbladnir."

It was a good thing the airship, provided by Dexlabs to ensure a speedy arrival, had multiple sleeping quarters. It allowed Numbuh Five's rookie team to go sleep off their jungle adventure separate from the gathering of equally tired, thoroughly baffled army commanders as they tried to make sense of what they'd seen that day.

"I thought this area had been cleared weeks ago," Kevin was saying from where he was sitting on the floor, back against the wall. He and Numbuh Five had led the fight against a surprisingly massive wave of fusion monsters, the likes of which had supposedly not been seen behind the carefully erected energy fences that had kept this area blocked off for some time.

"So did we," Numbuh Five said.

"And it was," Blossom agreed. She knew first had just how clear it had been—she'd personally lead the reconnaissance group that had done the final check of the area before announcing it clean of fusion presence.

"So Lord Fuse obviously decided that there was something, or some reason important enough to come back here for," Rex said.

"Maybe that base of his," Juniper suggested. "It seemed like a pretty serious piece of work to just abandon."

"I don't think so," Blossom said. "It wasn't there when we swept the place after it was contained. It must have been erected recently, in the last few weeks. The fusion monsters probably showed up then as well."

"But why?" Rex asked. "It's such a risky move on Fuse's part, isn't it? I mean, why would he bother putting so much resource into a place that was so likely to be discovered? He was right on our doorstep in this jungle."

"Was he?" Kevin asked, earning a confused look from Rex.

"He's on our captured territory. We would have found him eventually."

"I don't think so," Kevin said, shaking his head. "As bad as it sounds, the reclaimed zones don't exactly get checked on very often."

"It's considered a waste of a patrol," Blossom agreed. "We usually assign a few soldiers to watch the perimeter of a new area when we first acquire it, but after that, unless it's used for an operation's base, it gets pretty much abandoned."

"Ripe for the picking if you're an alien enemy who wants to work without being spotted," Kevin finished. "I bet if Numbuh Five and her team hadn't been heading this way then we might never have found the place."

"So the question isn't how Fuse got here," Juniper said, "it's why he's here."

"I think I figured that one out," Rex said, his expression darkening. "When I was in the base I was able to connect with one of the computers, although only briefly."

"And?" Kevin asked.

"And it was listening in on radio frequencies."

A sense of dread filled the room at Rex's words.

"What frequencies?" Blossom asked slowly. Rex sighed, meeting her gaze.

"All of them. Every single one on planet Earth."

"That's why he guarded it with those Fusions," Numbuh Three said, glancing at Numbuh Five. Her teammate nodded.

"Makes sense. If I was Fuse I would want to protect an advantage like that too."

"This isn't good," Kevin said, looking between his fellow commanders. "If this area has been pretty much abandoned for weeks…"

"And Fuse has been able to eavesdrop on us for almost that long…" Juniper continued. Silence hung at the end of her sentence, no one comfortable with voicing the terrible realization they'd all reached. Eventually it was Rex, his hands curled into fists, that whispered a tense, terrified,

"Fuse has been aware of or every move, every communication, for weeks now."

"What does this mean?" Numbuh Three asked softly. Kevin, meeting the girl's worried look, sighed.

"It means we might be really, really screwed."

The double doors opened into a small, dark space. The Professor ushered them all inside, allowing the door behind them to swing shut, sealing them into darkness.

"Where are we?" Mac asked quietly. Turning, he bumped into someone's side, Gwen's comforting hand appearing on his shoulder a moment later.

"This is the observation deck," the Professor said, his voice echoing from somewhere off to the side. "This is where Dexter and I come to check on how the construction on the Skid is coming along." There was a small click, like a switch being pressed, and the room flooded with light. The gathered commanders shielded their eyes, blinking at the change. "And there she is," the Professor was saying as the spots cleared from their eyes.

Gwen looked around the small room, a mostly steel-walled venture with a door in one corner and a pane of tinted glass covering most of the wall in front of her. Hesitatingly she moved towards the glass, glancing at the Professor as she did. He nodded his encouragement so she looked back, taking her first look at an interstellar space ship she'd never imagined could have existed right beneath her toes.

It was massive.

The ship's wide, solar glass paneled front stared down at them, allowing Gwen a chance to look inside the ship's vast control room. The thing was so big that most of its bulk was hidden from view behind its own wide girth, but Gwen could see the side walls of the massive hanger disappearing into the distance.

"It takes a crew of only one hundred men to run the fly, although it has room for ten thousand workers to help maintain the ship and care for its passengers."

"Do you have that many people available here?" Gwen asked.

"We have the flight crew, but we figured other jobs could be filled by passengers. It would give them something to do during the vast, empty hours of space travel."

"And this thing is ready to fly?" Numbuh One asked. "Right now?"

"It is," the Professor agreed. "She's never been on a test flight herself, but all of her components have to some degree. Every single one of the Dexlabs ships we're flying right now contains test versions of the Skid's every system. The passenger compartments are all ready to take on occupants, and the food stores are fully stocked. The ship even contains areas of technologically sustained farmlands so that the ship can continue to produce its own food supply."

"What about fuel?" Gwen asked.

"Once in space the ship is equipped with a range of sensors and adaptors, allowing it to draw power from virtually anywhere—sunlight, solar winds, even the gravitational pull of nearby planets and stars. Many of them were designed by Mr. Levin himself."

"And since you're showing us this now, that must mean you think an evacuation of the planet could be a necessary possibility," Mandy said, eyeing the Professor closely.

"Unfortunately yes," the Professor said, expression grim. "Gwen, what you and Mac noticed today is only one instance of a growing trend that we've been tracking over the last month and a half."

"We?"

"I've been working with some of your field commanders to try and map, and by doing so hopefully predict, Fuse's movements. My daughter Buttercup and Gwen's cousin, Ben, have been some of my primary help for this. What we've found seems to be mirroring Gwen's suspicions about the local fusion activity. Fuse is continuing to try and wear us down, but while he does so he also seems to be amassing troops. For what we weren't sure, but I think Numbuh Two's reconnaissance flight just might be able to answer, at least partially, some of those questions."

The Professor turned to one of the blank steel walls and pressed a section of it. The small square of steel turned red, a hidden palm scanner that verified the Professor's identity before retracting into the wall. A moment later and the entire wall began to move, once invisible panels turning and shifting outwards, the entire wall reconfiguring until it had gone from simple, plane surface to a complex computer terminal.

"Whoa," Mac breathed, eyeing the array of screens and flashing lights.

"This is where I've been tracking the fusions movements," the Professor said. On the computer's main large screen he pulled up a map of Heroes' Square the surrounding area, crisscrossed with a tangle of multicolored lines, patches of glowing red and blue marks, and a lot of blinking dots. "This screen is fed by real time updates from those in the field letting me know where fusion monsters are fighting and in what numbers. The areas of color are battles currently taking place, the lines mark known or suspected fusion routes, and the dots are the location of known Fusion copies. For example this section was just updated by Rex a few minutes ago." The Professor pointed to an area on the screen highlighted in red.

"That's where Numbuh Five's team was," Gwen said, moving to get a closer look at the map. The Professor tapped the newly lit area and the screen zoomed in on it, boxes full of various bits of data popping up around it. "Look," Gwen pointed to the two dots in the center of the red. "They saw two Fusions there!"

"Dexter and Bubbles," the Professor said, looking at one of the info boxes. He frowned. The Fusion copies of his daughters made him uncomfortable at best, and the idea of one of his daughters having to fight one was distressing.

"What are they doing so far from Hero's Square?" Numbuh One asked. The Professor shrugged.

"Unfortunately this system only tracks enemy movements. We won't know their motivations until the team arrives to tell us themselves."

"If this machine tracks movements then can it tell us what's happening here at Peach Creek and Dexter's lab?" Mandy asked.

"Hopefully. Dexter is supposed to send us whatever information he and Numbuh Two gather so that we can plan accordingly."

"And by plan you might mean…" Gwen trailed off, turning her gaze on the spaceship looming over them.

"Maybe," The Professor agreed softly.

"So when will we hear from Dexter?" Numbuh One asked.

"It should be any minute now," the Professor said, checking his watch. "As long as everything goes as planned."

"I'm sure it will," Gwen said. "With Numbuh Two and Dexter working together what could go wrong?"

"Would you stop that!?"

"Come on Dex, live a little!" Numbuh Two teased, although he eased the Odin back into its previously agreed upon flight path.

"I am living," Dexter said, "I just happen to be doing so without trying to break someone else's very expensive equipment."

"You know, I thought you were going to leave me alone until I reached the Cul-de-Sac," Numbuh two said, his fingers dancing easily across a bank of switches as he leveled out the Odin's flight.

"I thought you were going to behave yourself until then." Numbuh Two grinned.

"You have no idea how to show a lovely ship a good time." A sigh echoed over Numbuh Two's headset.

"Are you close yet?" Dexter asked.

"I'm within sight of the Cul-de-Sac," Numbuh Two said. He could just make out the tops of the cardboard barricade circling the Peach Creek neighborhood. "I do see much fusion activity from here, though."

"Do not let the quiet fool you," Dexter said. "We mustn't underestimate Lord Fuse."

"I know that," Numbuh Two said. "I'm going to drop in for a closer look."

"Then I will activate the stealth settings," Dexter said. A few of the Odin's screens flashed with little warning messages and then the cockpit lights dimmed. A whirring sound trailed over the ship's hull as whatever masking technologies Dexter had invented kicked in. Numbuh Two fidgeted in his seat, wishing he could see the ship from the outside.

"Thanks Dexter," he said. "I'm heading in now. Initiating radio silence."

As the Cul-de-Sac rose into view Numbuh Two took the Odin in a lap around the cardboard barrier, searching for signs of fusion monsters. He spotted one skirmish (it took all of his self control not to drop out of the sky and join the fight) but other than that there was little activity coming from the fusion-goo puddled streets leading into the Cul-de-Sac.

"It looks like Mac and Double D were right," Numbuh Two said as he circled. "There's only a small group of fusions here. All of their usual spawning grounds look deserted."

"Where could they have gone?" Dexter asked. "You didn't see any unusual fusion activity flying over, did you? Not that it wouldn't have been easy to miss among your tomfoolery."

"Dexter, I'm perfectly capable of scanning for a fusion army while flying formations. I wasn't picked to fly this thing for nothing." Dexter huffed noncommittally in response, which Numbuh Two took as acknowledgement that he was right. "Anyway, my question isn't just where this army went, but how did Fuse move them so quickly? It's not like we wouldn't notice a sudden fusion migration."

"There must be clues somewhere," Dexter said. "Head to my old laboratory. Focus your search on the entrance to the fusion's tunnels. They're how they have been trying to access—"

"Dexter," Numbuh Two said, cutting the inventor off. "Tunnels. If Fuse is using them to get into your lab he might be using them to move other fusions." Silence followed his words as Dexter considered their implications.

"Try using the thermal imaging to scan the ground around the Cul-de-Sac," Dexter said. "They could be using the same tunneling technology they deployed against my own lab."

"Aye, aye, Captain," Numbuh Two said, fingers dancing across the Odin's controls as he activated the ship's thermal sensors.

"The Odin will be able to pick up even the faintest of heat signatures," Dexter was saying as he worked, "Even just one fusion monster, miles below the surface, will register using this technology. If Fuse is moving his fusions underground then we will know about it shortly."

"Thermal imaging is online now," Numbuh Two said. "We should have an image in just a second." As he spoke, a little beep announced the ship's tiny monitor switching over to thermal view, the image the ship's sensors had captured appearing both on the consol and the larger screen back in Dexter's lab.

Both screens glowed red.

"Are you getting this, Dex?" Numbuh Two breathed, eyes riveted on the scan results before him. They had known, even without discussing it, that it was likely they were going to find fusions heading for Hero's Square. They'd been expecting a trickle, or a march, a flank of monsters heading for Sector V. But this, this sea of red—even on his darkest days Hogie couldn't have imagined forces like this.

A tiny, tense "Affirmative" answered his question.

"I think," Numbuh Two paused, a small, overwhelmed sound escaping him, "I think we might have a problem."

Deep in a bunker underground soft conversation stopped as a large, complex computer beeped brightly.

"It's Dexter," the Professor said as he moved up to the console.

"What have they found?" Gwen asked, she and the others moving up beside the scientist.

"We'll know in a moment." The Professor opened messages and input commands, adding the data Dexter had sent in to that already on the board. The map of the area zoomed in on Hero's Square, red blooming over the surrounding area. Stunned silence fell over the group as they stared. It was a long time before a soft, hesitant voice broke the silence.

"Are those…all fusions?" Mac asked.

"They are," the Professor said, voice strained.

"They're moving," Numbuh One said. The red on the map swelled as Dexter's data continued to pour in, showing a broad ring of glowing read that was steadily closing in on the heart of the war efforts. And then the computer was beeping, messages popping up along the sides of the screen as more data came flowing in.

"Dexter?" Mandy asked.

"No, these are coming from the field," the Professor said, scrambling to keep up with the sudden influx of data. With each bundle of data he added the map zoomed to a new location, each time displaying a sudden surge of fusion activity, red splotches spreading all over the map.

"What's happening?" Mac asked, scooting closer to Gwen.

"Fuse is—we've never had a concentrated attack like this. He's, how could this happen?"

"We need to get back to the treehouse," Numbuh One said, already heading for the door. "We have to set up a perimeter, start recalling any soldiers we can back to base to help fight."

"What good would that do us?" Mandy asked, motioning to the glowing red screen. "Do you really think we have the fire power needed to stop that kind of attack?"

"What do you suggest we do?" Numbuh One asked. "We can't just hide down here and wait for it to pass over."

"And getting ourselves killed is a better alternative?"

"Guys, stop," Gwen said, moving herself between the pair. "This isn't helping. Mandy's right. This…this isn't anything we were prepared for. We don't have the kinds of man power needed to fight this. I don't know how Fuse managed to plan something like this but we don't have time to figure it out. We need to act, and right now the most important thing is protecting as many of Earth's people as possible."

"So what do we do?" Numbuh One asked. Gwen turned, directing her gaze out the room's one window towards the secret space ship she could never have imagined existed.

"I don't think we can stop this one," she whispered. "But we can still save as many lives as possible."

"The ship's ready," the Professor said. "Say the word and we'll make the call to have all troops recalled to DexLabs. This whole building was designed to accommodate an evacuation; in twenty minutes we can have it ready to begin loading."

Gwen turned to the Professor and her fellow companions. Fear and uncertainty, wavering with stubborn determination, echoed back at her from their wide gazes. Though they'd always shared their duties of command, when it came to decisions concerning space and its uncertainties they'd always turned to her, to Ben, to Kevin for answers.

"We can't stop Fuse. If we stay and fight we'll only be destroyed," she said slowly, realizing the weight choice she was about to make for them, "But even if we can't save our planet we can save even a fraction of its people, and against Fuse, whose only goal is our complete annihilation, I think that's still a victory. In the end we have to do what's best for Earth, and now that's to do everything we can to save those of Earth that we can still help."

Silence followed her words. Their collective fear hung between them. This was it, the final decision on Earth they might ever make. Such a thought was terrifying.

But the prospect of death was even more so.

"I'll contact the treehouse," Numbuh One said, "Let them know that all troops are to fall back to DexLabs."

"I'll contact Dexter. We'll start the evacuation procedures immediately."

"Good," Gwen said. "Mandy, can you let Grim know that he should relocate all of his resurrection points to bring any fallen soldiers back to Hero's Square?" Mandy, the only person known to still have contact with Grim since he'd officially vanished some time ago, nodded.

"So, is this it?" Mac asked softly, drawing the room's attention to him. "If we're all leaving, does this mean the war over?"

"Not yet," Gwen whispered. Behind her the Professor's computer's screen glowed red, accentuating her words. "The final battle is just beginning."