Nearly two hours after Perry the Platypus had defeated him, Dr. Doofenshmirtz returned to D.E.I. fuming - not just because of the actual fumes, but because he was angry.

"How," he thought aloud, "can I finally defeat Perry the Platypus? I mean, it's fun being his nemesis and all, but can't a guy's evil schemes succeed at least once? I've got to think of a plan… and not just one that involves seeking revenge for something that happened when I was a child and then building a device called the 'Whatever-I-Want-to-Do-inator!' This is going to take some serious planning."

He walked over to his balcony and stared out at the spectacular view of Danville, its suburbs, and the rest of the Tri-State Area. Somewhere, he thought, Perry the Platypus is at home. Maybe he lives in special OWCA lodgings, or maybe he is a pet! Yes, I seem to remember an inator that was supposed to spy on Perry the Platypus. I saw a house and some kids. But then it got destroyed; as usual.

Suddenly, inspiration struck. "That's it!" he cried. He started dancing around his building. "I'll kidnap someone who's close to Perry the Platypus! Then, I'll hold him - or her - for ransom until the OWCA agrees to let me carry out a scheme unthwarted… and it'll be my best scheme yet! Now, what kind of inator will I need?"

The excitement had worn him out. He would plan while he dreamed… or in the morning…

He fell asleep.

It was a typical day for Perry. He was about to use his favorite secret entrance, but he was waiting. It wasn't necessary, but somehow it was reassuring.

"Hey! Where's Perry!"

Satisfied, he pushed the spigot of the hose into the house. The circle of grass he was standing on slid away and he fell into the freshly waxed glass tube.

Five minutes later, he was jet-packing to Doofenshmirtz Evil, Inc. He wondered what kind of inator he'd be destroying today. He flew into the main lobby, called the elevator, and waited. When the elevator arrived, he hit the button that would take him to his mission.

"CURSE YOU, PERRY THE PLATYPUS!" screamed Doofenshmirtz, but he wasn't able to hold it for as long as usual. As soon as Perry the Platypus was out of earshot, Doofenshmirtz stopped holding in the laughter. Sure, the Averaginator had been cool, but it was only a decoy. The past three weeks had been an enormous crescendo of happiness and excitement, and today was almost the culmination. Tomorrow, his plan, his beautiful, wonderful plan, would finally come to fruition.

And Perry the Platypus hadn't noticed a thing! That had been the part that had worried Dr. D the most. If Perry the Platypus had caught on at any point in the process, it would have been devastating. But Doof had been able to create his Touch-Activated Teleportinator. It had been successfully implanted in Perry the Platypus' skin. All Doofenshmirtz had to do now was make a few finishing touches to the Devolitioninator.

"Oh, there you are, Perry," said Ferb when he felt the platypus brush against his leg. He picked Perry up. Ferb loved everything about platypi. They were his favorite monotremes. He had recently discovered that the platypus was not the only mammal to lay eggs, but he still thought it was cooler than the echidna.

Ferb's train of thought was interrupted by a ray of green light. It bathed his creation - Phineas hadn't contributed, because they had had an argument earlier - for a moment, and then all that was left of the day's efforts was an E-Z Bake Oven.

Ferb sighed. He sometimes wished Candace would succeed in "busting" him and Phineas. At least Mum would see. At least the things would last past sundown. That was the worst part. Every day, he poured his heart and soul into these contraptions, and every day, they would disappear or shrink or be transformed into something entirely different.

"Mom! Mom! Phineas and Ferb made something that prepares the best food ever!"

"Good, then I won't have to make dinner." She saw the plastic, lightbulb-powered oven.

"Candace…"

"Mom! I swear! It was right there a minute ago!"

Ferb sighed again. Poor Candace, he thought. He put Perry down and went to get ready for dinner.

Ferb went to bed a half-hour before he and Phineas normally did. He was tired from building the device entirely single-handedly. Usually, he only built things mostly single-handedly.

As tired as he was, Ferb wasn't able to fall asleep until Phineas came in. He was hurt when Phineas didn't say goodnight. Perhaps he had assumed Ferb was already asleep. Maybe he was still mad. Whatever the reason, it was only three minutes before Phineas started snoring. Comforted, Ferb fell asleep.

Perry woke up at 12:30 AM. He crawled out of Phineas' bed and over to Ferb's. It was part of his routine. He'd spend three and a half hours in Phineas' bed, three and a half in Ferb's, then 90 minutes in each. Every other night, he would alternate which bed he'd start in.

Perry snuggled in next to the still, warm body. Some part of Ferb's mind registered his presence, and he put his arm around the platypus. Ferb's hand touched Perry's fur for the third time since Perry had come home. If he had been awake, he would have noticed a slight stinging sensation. However, he was deeply asleep and didn't even recoil.

Twenty minutes later, an alarm beeped and awoke Dr. Doofenshmirtz. The transfer was complete. Doofenshmirtz had designed a device that would "piggyback" nerve signals, identify the first person to touch Perry the Platypus three times, and then transfer itself to the person. When it was done, it would send an alert to Dr. Doofenshmirtz so he would know his victim was ready. All he had to do was wait until Perry the Platypus got up, which happened at around 4:00. Once Perry was settled in Phineas' bed, there was a flash of light, and Ferb was gone.

Ferb woke up. He was cold. Where's my blanket? he thought. The surface he was lying on was hard. Where's my bed? He opened his eyes. Where's my room? Ferb was bewildered and frightened.

"Phineas?" he said aloud. "Perry?"

Ferb blacked out for a moment and came to feeling even more miserable than before. He was so tired… and cold… He tried to get up, but he couldn't do more than raise himself onto his elbows. He let out a breath in frustration and fell on his face again.

Suddenly, inexplicably, rage kindled inside him.

"Let me out!" he screamed. "Letmeoutletmeoutletmeout!"

He ran to the door and started banging. Slowly, the rage ebbed. His brain turned on. He felt around in his pocket for his picks, and was pleasantly surprised when he found them. Picking the lock was easy. Ferb opened the door and stepped out.

Wham! Something hard hit his head, and he blacked out again.

Ferb came to. There was a strange buzzing sound in his ears. His vision was blurry, and he blinked several times to clear it. When he could see normally, he was amazed.

It was darker than the room he had escaped from. Lurking in the shadows like nightmares were several angular contraptions. Ferb relaxed a little bit. He felt more comfortable around machines, because they didn't expect you to talk to them.

The man standing directly in front of Ferb, however, completely undid any relaxation brought on by the machines. For one thing, he fit the bill of "stereotypical evil and/or mad scientist" perfectly, and for another, he was holding a sinister-looking remote control.

Ferb decided to attack. It didn't seem like this guy would have let him leave otherwise. Ferb didn't like violence, of course, but he could look after himself and would attack when provoked. If his mother asked, he would tell her that being kidnapped in the dead of night counted as provocation.

He ran at his captor and was about to start assaulting him when, against his will, he stopped dead in his tracks. It was as if he'd run into an invisible cube of quick-drying cement just before it dried. He was completely unable to move any muscle. He couldn't wiggle his toes. He couldn't blink his eyes. He couldn't even hold his breath. It seemed like he couldn't move any of his muscles voluntarily.

He glared at his remote-wielding enemy, who laughed and said, "Behold… the Devolitioninator!" He pulled a curtain away from a mirror, and Ferb saw himself.

His pajamas were rumpled, his sore limbs were frozen stiff in awkward positions, and his face had a stupid half-angry, half-stunned expression. There was an oddly familiar helmet on his head, which he assumed must be the Devolitioninator.

Volition is your will, he thought, so this helmet thing must somehow be controlling me. Ferb was impressed against his will. However evil it might be, this was an amazing invention! I must tell Phineas about this. Just imagine the practical applications! It could be used to help paralytics move, or restrain captives… like me, for instance… or -

Ferb told himself to focus. The evil scientist was starting to speak.

"I am Heinz Doofenshmirtz, the nemesis of Perry the Platypus -"

I knew it! This must be where Perry goes!

"- and I have captured you to fulfill my evil scheme. I apologize for any inconvenience this might cause you -"

Then why don't you let me go?

"- but you are closely acquainted with Perry the Platypus, and there is no other way to get the OWCA to allow me to carry out one of my evil schemes unthwarted. You see, Perry the Platypus always defeats me, and, to be honest, it's really irritating. Sometimes, I come up with really good ideas, and Perry the Platypus just destroys my inators. This time, I will take over the Tri-State Area! I will succeed! And I can make everyone change their name to Joe! You see, back in Gimmelshtump, there was a boy named Joe who always called me a schnitzel... "

This is ridiculous. I want to go home.

"... and in conclusion, that's why I want everyone to be named Joe so I can feel better about being cruel to them. Well, Joe, let's see how long before they notice you're gone."

Phineas woke up. It was still dark out, but something was wrong, and he couldn't sleep.

"Hey, Ferb. I'm really sorry about yesterday. I shouldn't have yelled at you or called you stubborn."

There was no reply.

"Ferb? Are you awake?"

Phineas got up. Ferb's bed was empty.

"Perry, wake up! Ferb's gone!"

Perry woke up at once. He chattered, and, deciding it was an emergency, whipped out his fedora and put it on. He shushed Phineas when he opened his mouth to speak, and beckoned him to follow. The two climbed out the window and entered the OWCA lair through an entrance Phineas had used before.

"Agent P? What are you doing up so early? Great googly-moogly! Agent P! What's the boy doing here?"

"Ferb's gone missing!" wailed Phineas.

Perry chattered.

"Uh… Agent P, go check up on Doofenshmirtz. Find out if he's up to this."

Perry saluted and jet-packed out.

"Well, Phineas, you should wait here. I'll send Carl over to keep you company."

Several minutes later, a door opened and a boy about Candace's age walked in. He had curly red hair and glasses.

"Hey, I know you!" Phineas said. "You're the kid who played with the Anti-Gravity Fun Launcher."

"That was the best day of my life, actually. Thanks."

And the two lapsed into silence, staring at the clock, waiting for Perry to return.

"Ah… will you look at that! It's Perry the Platypus!"

Ferb's stomach lurched, and he felt the awful sensation of being forced to walk over to the balcony and look in the direction indicated.

"You know, Perry the Platypus always manages to escape my traps and defeat me, so I'm going to have you fight him."

You can't make me do that. There is no way you could make me do that.

Less than a minute later, Perry landed on the balcony, and, to his horror, Ferb launched himself at Perry as though they were mortal enemies. He hoped that Perry would beat him, but he had the upper hand and quickly incapacitated the platypus and tied him securely to a chair. The worst part was that he wasn't able to turn away from the heartbreaking look Perry was giving him. He was almost relieved when Doofenshmirtz made him walk back to his side like a puppet.

Phineas was anxious. He was also irritated at Carl and Monogram for worrying more about Perry than his brother.

I need to do something, he thought. Then a plan sprang to his mind.

Phineas dug around in his pockets, and found some building scraps. Nearly every day, Phineas put a screw, or bit of metal, or bolt, or screwdriver, or anything else, in one of his pockets. He saved the pieces for when he was bored, and he had luckily not forgotten his pajamas.

He tinkered around until he had made a small windup toy. He wound it up, then gently set it down.

It scuttled over to the place where Perry always sat, and crawled on top of the control panel. It immediately started to mess around with wires.

"Hey - don't touch that!" said Carl, running over to the control panel. Monogram's image disappeared from the screen. Phineas ran to the small vehicle he had used once before and made a speedy getaway.

Ferb hated himself. He couldn't believe Doofenshmirtz had been able to control him that easily.

His heart ached for Phineas. He felt as though he'd had half of himself ripped away. The worst part was that they were angry at each other. I'm going to apologize to Phineas the second I see him, thought Ferb.

He was pacing around the balcony. Doofenshmirtz had decided Ferb would make a useful lookout.

"You see," the doctor had said, "originally I just wanted to use the Devolitoninator to keep you from escaping, since I'm not good at designing escape-proof traps. But then I realized that you had - what do you kids call it these days?- mad skills, and I decided to put them to use."

Part of Ferb's robotic strolling around gave him a glimpse into Doofenshmirtz in his office. Every few times, he would say something that was supposed to be encouraging, like "Keep up the good work!" but it only made Ferb feel worse.

One time, he saw a picture of Vanessa on his desk. Great. He thought. Just great.

At 6:37 AM, he saw something that made him stop. (Doof had ordered him to stop if he saw anything approaching the building.)

After about 20 seconds, Ferb did a double take. He recognized the triangular head of the person driving the air vehicle approaching the building.

Phineas? Ferb groaned. He suspected that Phineas had discovered he was missing and decided to take matters into his own hands.

Well, that's it. You can make me walk around. You can make me do your bidding. You can even make me fight my own platypus! But you cannot ever say, or do, or invent anything that could possibly make me harm my own brother!

Phineas landed. He saw Ferb.

"Phineas! No!"

Ferb charged, but he was fighting himself. Even though his legs were running as fast as they could carry him, he had clenched his teeth and was holding his breath in concentration. If he had noticed that, he would have realized he was halfway there. He had gained control over some muscles without realizing it. But it didn't seem to be enough.

Phineas saw his brother running at him with an intense expression on his face.

"Ferb? Are you still mad about yesterday? I said I was sorry!"

The sound of Phineas' voice did it. It gave Ferb's willpower a big enough boost to completely fight off the effect of the Devolitioninator.

From a combination of his struggles against the Devolitioninator, the shock of winning the fight, and lack of air, Ferb collapsed into a dead faint at Phineas' feet.

Phineas removed the helmet from Ferb's head. He walked over to Perry, found Ferb's special knot, and freed the monotreme, who saluted him and jet-packed away. He snuck into Doof's office, where the scientist was busy chatting on his computer, and planted the helmet onto his head. He walked him onto the balcony, tied him to the empty chair, and used the communicator in the air vehicle to contact the O.W.C.A. Finally, he carried Ferb into the air vehicle and drove off.

Ferb came to as they were flying.

"Thanks," they both said.

"Sorry," they said in unison.

The boys laughed for a few moments until tears came to their eyes. Phineas took a ten-second break from driving to embrace his brother. Luckily, the ship had an automatic auto-pilot that would activate once the wheel was no longer being touched.

"By the way, Ferb, I found out you didn't actually build all this cool stuff. It was kind of a letdown."

The air vehicle parked outside the boys' room, allowed them to climb inside, and automatically returned to Perry's lair. Ferb collapsed onto his bed, and Phineas sat down on his, surprised to find that Perry was already there, sleeping as though the night before had never happened. Phineas wondered if he was allowed to know about Perry the secret agent. Maybe he'd write a letter to himself, just in case.

The alarm clock rang. It was 7:00 AM.

"Hey, Ferb. I know what we're gonna do today-" began Phineas. But Ferb had other ideas. It had been a tiring ordeal, and he hadn't got much sleep the night before. He cut Phineas off before he could finish.

"Take a nap."