Somewhere in the Andes, looking very out of place among the rocks and trees, sat a blue police box. Nobody was around to notice except for a few curious animals that had ambled over to investigate.

"Tegan, what are these?" Nyssa asked as one of the creatures leaned down to get a better look at her.

"Llamas," replied Tegan, "I think they'll let you pet them if you like." She reached up to pat one on the side. Nyssa tried to stroke the neck of the nearest llama, and it gave her a nudge that made her lose her balance and fall to the ground. "Don't worry. They're friendly."

"I can see that." The llama stuck its head in her face, ears alert as if concerned it had hurt her. She gently patted its nose and it snorted.

A short distance away, Turlough wandered aimlessly along a shallow stream. Occasionally, he chucked a rock into the clear water. Tegan kept an eye on him. She couldn't quite put her finger on it, but there was something about that boy that made her suspicious. Maybe it was his attitude, or that he had unusual knowledge for an Earth schoolboy, or maybe it was the time she caught him talking to a murderous paperweight. Whatever it was, she didn't trust him, and she didn't understand why the Doctor did.

Speaking of, once he'd determined there were no threats in the area, the Doctor had herded the three of them out of the TARDIS while he stayed inside to work on something.

"Is he ready to leave yet?" asked Turlough, coming back from the creek, "This place is boring."

"I like it," said Nyssa. The llamas had taken a shine to her and most of them had settled down next her on the grass. She sat against one while petting the nose of another.

Tegan felt a drop of water land on her nose and looked up at the gathering clouds. "I think it's going to rain soon," she said, shivering. She decided to join Nyssa with the llamas; their wool looked much warmer than her jumper. Meanwhile, Turlough was staring back at another llama that had walked over to examine him, trying to determine whether it was nice or not.

"Nyssa! Tegan!" called the Doctor, "Come in here! I think I've done it!"

With a quick look at each other, the girls ran inside the TARDIS. They found the Doctor had arranged a series of circuit boards in a circle, each attached to what looked like a solar panel. A tangled mass of cables haphazardly connected them all and ran to an open section of the console. In the middle of it all stood the Doctor, looking like an overexcited puppy.

"Artron energy!" he said. "The TARDIS is full of it, and you've both accumulated some from your travels. Not enough for you to notice, of course. More like a light dusting. But I think," he went on, "that if I've set this up correctly, I should be able to use the TARDIS to accelerate you to your proper ages."

He paused to wait for their reaction. Before either of the girls could speak, one of the panels sparked and fell over. "Are you sure, Doctor?" asked Nyssa as he righted it.

"I'll tell you what- we'll test it out first." He stepped out of the room and came back a few seconds later with a potted fern, which he placed in the center of the panels. "Now, just a few adjustments to the controls and..." He twisted some dials, flicked a switch and the machinery powered up with a low whine. The fern trembled...

...and promptly exploded.

"No luck then?" asked Turlough, having just come in.

"I suppose not," said the Doctor, disappointed. He powered down the machine and went to examine it. "Hmmm...we're going to need an entirely different cable. It looks like this one is-" Something ticked his neck from behind. He turned around to find one of the llamas had wandered in. "Who left the doors open?"

Tegan and Turlough pointed at each other. Several more llamas entered, wondering where their friend had gone.

"Oh, no," said the Doctor, "Not in the TARDIS!" Standing up, he went to push the first llama out the door, but it started to rain heavily and the rest of the herd hurried inside. In the confusion, the machine started up again, was knocked over, and electrocuted quite a few llamas before the Doctor was able to shut it off.

Finally, they managed to coax all two dozen of them outside. The llamas watched as the TARDIS dematarialised, fading away like an echo.

"Did anyone else see that?" one asked.

It was easy for Henderson to get into the Cobb building. A fake ID, a few carefully-chosen words, and a bit of flirting with the receptionist gave him access as a potential investor.

His guide showed him around the facilities. "Very modern. Most of our worldwide branches have been updated, and we're looking to renovate the rest. Now, here is the main lab. We have scientists from over twenty countries collaborating on various projects..."

"I hate to interrupt, but you're quoting your own website," said Henderson. He gestured to his glasses, where he'd brought up the relevant page on one of the lenses.

"Ah, sorry about that, sir," the guide said apologetically. "Forgot you're not one of the tourists."

"No."

"Well, how about we talk to the woman herself? I can see if Ms. Llewellyn is available."

"That sounds all right."

While he waited for the guide to go see where she was, Henderson took the opportunity to activate another program on his glasses. It was a special recording program that would capture all audio/visual in the area without being detected. (His e-pad had been confiscated by security before he'd been allowed in.) Anyone looking at his lenses from the front would only see a very basic note-taking program.

After waiting patiently for a few minutes, Henderson decided to take matters into his own hands. He headed off in the opposite direction. Nobody stopped him; he'd had a lot of practise with walking around like he owned the place. Past the labs, past the meeting rooms and testing arenas, up the lift, down another hall...

Eventually, he found the office he was looking for. Making sure he was unobserved, he cracked the electronic lock and slipped inside.

He was pleased to find she'd left her computer on. Even more when he'd been able to guess the password. (Really, "Password1"? This was going to be easier than he thought...)

Rival corporations all over the world would have killed to learn how Llewellyn had expanded her company to such an extent in such a short time. Henderson was sure they'd sent their spies to uncover secrets and strategies. But he wasn't here for that. No, his employers had sent him for a much different reason. Suspicions of illegal activity, evidence of disregarding health and safety regulations, allegations of fraud and tax evasion...just your average corporation stuff. He needed hard evidence of wrongdoing before any charges could be brought.

What he found was so much worse.

He almost didn't believe it; almost walked away right there, but he had to send the information along regardless. Horrified, he dutifully recorded everything the computer had to offer.

"Are you finding everything all right, Mr. Henderson?" He nearly jumped out of his skin at the sound of her crisp voice. When had she entered? Why hadn't he heard?

"It's too late for you," he said. "I've already got what I came for. You might as well put an end to this, because the authorities will be on you any moment!"

"Unlikely." Llewellyn grinned at him. It wasn't a pleasant one. "Better men than you have tried to stop us, but I'm afraid our plans will be going forward whether you like it or not."

"It's true, then? This...madness?"

"Of course."

He looked at her with disgust. "But they're just children!" he exclaimed. "What kind of monster are you?"

Still smiling sweetly, Llewellyn tapped a brooch on her lapel. Henderson watched, eyes wide, as her form changed. "No...no! Get away! Get-!"

His screams echoed down the hall.

Nobody seemed to notice, except for the guide. He calmly strode down to her office and knocked on the door. She emerged, completely normal save for the blood on her dress suit. "Is anything the matter, ma'am?"

"Call maintenance. There's a mess all over the carpet in there."

The Doctor gazed around the shop suspiciously. Something was amiss here. "I don't understand it," he said. "We're nowhere near the 1990s! How could Radio Shack possibly still be in business?"

"I don't know, sir. I just work here," replied a bored employee. "Are you looking for anything in particular or just browsing?"

"Browsing."

The employee wandered off, leaving the Doctor free to search for a new cable. Turlough had wandered off to the other side of the store, and Nyssa and Tegan were checking out a keyboard on display. It sent up different-coloured holograms each time a key was pressed, and they tried to see how many pictures they could send up at once.

Walking up and down the aisles, the Doctor looked around to determine what year it was. Holograms appeared to be popular in this decade. Judging from the smartphones on display, they seemed to have stopped getting smaller. Posters advertised various models as being easier to hold onto and less likely to get lost in pockets. Definitely somewhere in the late 21st century, then. Satisfied with his deduction, the Doctor started making his way across the store when something on the shelf caught his attention.

It was a police scanner. At least, that's what it was being marketed as. On further inspection, the Doctor realised not only could it detect police cars- it could pick up any emergency vehicles, aircraft, satellites, and passing spacecraft within five light years of Earth. Detect and destroy them, actually.

"Doctor," said Turlough holding up a coil of red cable, "is this the one you're looking for?"

"What? Oh, yes...come have a look at this, won't you?"

Shrugging, he ambled over. "What is it?"

"A scanner." The Doctor explained what the device could do.

"So?"

"It's out of place for this time. Humans shouldn't have access to this level of technology yet."

Turlough took the item and looked it over. "It's just a cheap scanner. Maybe it's a fluke?"

"A very interesting fluke," the Doctor said . "One that could cause destruction on a massive scale! But who made it? What company?"

"There's a logo...Cobb Research Solutions."

"I think we ought to pay them a little visit. But first..." He flagged down a nearby employee. "Excuse me, but how many of these have you sold today?"

"What, those?" she replied, taken aback by his urgency. "I don't know. We only got them in today."

"Have you sold them before?"

She shrugged. "I don't think so. I mean, I haven't seen them before today. They're probably a new line or something."

"You wouldn't happen to have any more in the back, would you?"

"No, what's out here is what we've got. Can I help you with something, sir?" she asked pointedly. The Doctor looked back at the scanner for a second. He'd come on too strong, he suspected. She was sure to keep an eye on him in case he tried to shoplift anything. Putting the scanner back on the shelf, he said, "Oh, not really. Just curious. I'm actually here to get something for the kids." He gestured toward Nyssa and Tegan, who'd lost interest in the keyboard and were now looking up at a shelf full of puzzles. "But I think my friend here wanted to ask you about some cables." He smiled brightly at Turlough, hoping the boy would pick up on the hint and distract the girl.

"No, I didn't."

The Doctor decided to give the girl the hint instead. "Sure you did! You were going to ask silly questions and then ask her out. Oh, you probably didn't want me to mention that bit." The girl was laughing too hard to notice the bewildered look on Turlough's face, but she did look him up and down appreciatively and pull him to the other side of the room.

As soon as she was distracted, the Doctor grabbed one of the scanners again, popped open the casing, and ripped out three red wires. With a snap, he closed it again and slipped it into his pocket. Glancing up, he saw that the girl was busy flirting with Turlough. Good. She was into awkward gingers. Quickly, he repeated the procedure with the other scanners while she wasn't looking. He was just pocketing the last one when the store manager came by and saw.

"HEY!"

Before the Doctor could respond, there was a loud crash from the next aisle over. He turned and saw Tegan standing on tiptoes beside a shelf, reaching up to where the top level used to be before its support hinges unlocked and dumped all the merchandise on the floor. Sitting in the middle of the mess was Nyssa, looking dazed.

People were staring, and the manager was turning purple. "Time to go!" said the Doctor. Quickly, he scooped her up and dashed out of the store. Turlough broke away from the girl and waved the cable.

"But what about-! Oh, forget it." He dropped the cable, picked up a protesting Tegan, and ran after him.

The hooded figures gathered around a stone table. A handful of torches along the wall provided the only sources of light, and their shadows flickered and danced. "Henderson has failed us," said one of the figures.

"No," said another, "we have failed him. Henderson is lost."

"Lost!" went the whisper around the table. Their voices had an almost musical quality.

"Before his death, he was able to send the information. It is just as we've feared!"

"Then we have failed our mission. The evil ones have succeeded!" Several of the figures let out a moan of despair, but fell silent when the leader held up a limb.

"They will not win," it said, voice echoing in the dim room. "The watchers have brought me good news. They have returned."

There was a reverent hush.

"You don't mean...?"

"Yes. They have returned to us, as foretold by the prophecy of our elders, to help us defeat the evil ones."

"Forgive me," began one of the other figures, "but what proof is there?"

"The watchers have seen the blue box..."

The Doctor was pleased to find that the Cobb building happened to be only a few blocks away. Turlough was just happy they'd arrived, since Tegan was getting restless.

"Stop kicking me!"

"You can put me down now. We're inside," she snapped, wiggling to get free. He dropped her a bit roughly, but she shook it off and went to go stand with Nyssa.

The lobby of the building was a bright, airy place. Strategically-placed potted plants and a few fountains gave a somewhat calming effect, and a couple of futuristic television screens projected 3D images of local news events. On the low tables were some sort of digital tablets, probably the magazines of this decade.

Tegan picked up one of the 'magazines' and examined it. "What did we come here for?"

"I'm not sure," replied Nyssa. "The Doctor said something about anachronistic technology."

"I don't know who's behind this" the Doctor was saying to Turlough, "but judging from the time period and which interstellar trade routes cross this sector, I can narrow it down to a few dozen."

A woman emerged from a door behind the reception desk. "Welcome to Cobb Research Solutions!" she said. "Can I help you?"

"Yes, I'm the Doctor-"

"Oh! We've been expecting you!" she exclaimed.

The Doctor was momentarily taken aback. "You have?"

"Yes. One moment, please." The receptionist pressed a few buttons on her headset, "Sir? Dr. Peterson is here. ...Yes...yes, he's brought his own assistant..."

Ah, that was it. He'd been mistaken for someone else. It couldn't hurt to go along with it for a while. After all, it'd save him the trouble of making up his own credentials, and he could get in and take a good look around the facility. The receptionist finished her conversation and turned back to him with a smile. "They can see you now, Doctor. If you and your assistant will just take the lift to the fifth floor..."

"Thank you." He went to pick up Nyssa and take Tegan's hand.

"...but I'm afraid the children will have to go to the nursery."

She missed the look that passed between the two girls. "Couldn't they come with us?" asked the Doctor, sensing an impending mutiny. "They're very well-behaved."

"I'm sorry, sir. It's company policy, but I can assure you that we have some of the best child care facilities in the country. It's right down that hallway, you can't miss it. Just check in with Dave at the door."

The Doctor gave her a little smile and started walking in the direction she'd indicated. Turlough followed a few steps behind.

"Doctor," asked Nyssa as soon as they were out of earshot, "couldn't Tegan and I just wait in the TARDIS?"

"Perhaps. But we're already here, and I need to take advantage before the real Dr. Peterson turns up."

"So have Turlough take us back!"

"Look, it'll only be for a little while."

"Doctor..."

"I'll explain later."

They were already there. A low wall divided the waiting area from the actual nursery. Embedded into the wall was a door with a ledge on top, and a desk next to it. A dark-skinned young man looked up and smiled as they approached. "Hi! I'm Dave. And who's going to be joining us today?" he asked cheerfully, directing the last part at the girls.

Tegan, who'd been trying to tug her hand back the whole walk, finally broke free and ran back the way they'd come. With a startled shout, the Doctor spun around, thrust Nyssa into Turlough's arms, and chased after her. Looking somewhat out of his depth, Turlough turned back to the man. "Um, yes. We're here to check in, I guess."

"Name?"

"Turlough. And he's Doctor...Peterson." He gestured vaguely back toward the main lobby. They could hear several shouts of "No!" and something being knocked over.

The man typed in the information. "And is he your husband?"

"What?" asked Turlough, trying to keep a hold of Nyssa who was fidgeting to get down.

"Partner?"

"What does it matter?"

"Company policy says kids can only be picked up by a parent, family member, or an approved guardian."

Wanting to get this over with quickly, he replied, "Just put down approved guardian."

"Oh...I already put down 'partner'..."

"...okay, fine," he snapped.

"All right. And what's her name?"

"Nyssa," he said as she nearly slipped out of his arms. From the lobby came the unmistakable sound of shattering concrete, water, and the receptionist shouting something.

"Oooh, Nyssa!" said Dave brightly, "That's a pretty name. Here you are..." He'd printed out a blue name tag with her name and personal information to stick to her shirt. "And her sister...?"

"Tegan," replied the Doctor flatly, carrying the sulking toddler. He left behind a trail of footprints; water and dust from a broken fountain. Dave printed out another sticker.

"You two are in the Blue Group. That means you get to go with Mandy!" he said with an enthusiasm no one else felt. A plump, smiling girl approached them from the other side of the wall. "Mandy's one of our newest Carers, but she's very good."

Turlough handed Nyssa over the wall to the other girl. "Hello, there!" she said, "We're gonna have lots of fun today!" She tried to set the little girl down. "Why don't you...no, stand up, sweetie...just stand...no...don't..."

"What's the matter?" asked Dave.

"I can't put her down. She won't lock her legs!"

The Doctor opened the door and stepped forward. "Here, let me have a word with them before we leave." Nyssa ran up to him and he crouched down to address both girls.

"Doctor!" hissed Tegan. "Don't make us do this!"

"Listen, there's something odd going on around here. This company is manufacturing weapons that shouldn't exist in this time an place. I've disabled the ones from the shop, but I need to find out how many more there are and who's doing this before something serious happens. You and Nyssa will be safe here while Turlough and I investigate."

"But-"

"Brave heart, Tegan," said the Doctor. "We'll only be a little while, I promise."

With that, he stood up and walked back out into the smaller lobby. Mandy shut the door behind him and took the girls' hands to lead them to the play area. "Brave heart," muttered Tegan. "If we survive this, I'm going to smack him with his own celery..."