Doofenshmirtz's father came up from behind and clapped Doofenshmirtz on the shoulder, making him jump. "(Good news, dear!)" he said to his mother. "(This American is here to take Heinz away forever!)"

His mother seemed a bit less happy about that than his father, though she didn't look unhappy, and Roger just looked confused. But even though he should have been overjoyed, Doofenshmirtz's younger self cringed, trembled, and squeezed Perry the Platypus so hard that he looked like he was in pain.

"(No!)" he yelled, not seeming to notice Perry the Platypus's struggles, which suited Doofenshmirtz. "(I'm not crazy! Don't make me go with him!)"

What was he talking... Oh, right. Doofenshmirtz suppressed a shudder as a horrible memory came back to him. No wonder he was so upset. He laughed, both to calm his younger self, and to push that memory back where it belonged. "Oh no, (I'm the good... I'm not that kind of scientist. I'm here to, uh...) How can I put this... (Give you a good home.)"

Heinz didn't seem convinced. He looked at Doofenshmirtz warily. He didn't appear to be hurting Perry the Platypus anymore, but for some reason, Perry was still struggling. Doofenshmirtz concluded that he was struggling because he wanted to kick Doofenshmirtz in the face again, and glanced around the room for anything that could be used as a trap. The pot of food was a possibility, but then it would smell like platypus, and that would be such a waste...

"(It's already been decided,)" Doofenshmirtz's father told Heinz. "(You're going.)"

His mother jerked in surprise. "(What? I didn't agree to that.)"

"(He's come to take the boy away!)" said Doofenshmirtz's father, like that explained everything.

"(Forever?)" said Roger. He sounded sad, but that was obviously just wishful thinking.

Doofenshmirtz's mother put her hands on her hips. "(I wish you'd stop promising our sons to strange men!)"

"(But it's just Heinz this time,)" protested his father. He'd never known what to do when his mother got upset.

"Perry the Platypus, back me up here!" said Doofenshmirtz. His mother could ruin everything, though he couldn't help a feeling a little gratified that she didn't want to send him away anymore.

Perry the Platypus stopped struggling for a second and shook his head.

"What, are you still going on about your futzy space-time continuum?" He'd always known that Perry the Platypus could be a real jerk sometimes, but this... He'd outdone himself. The space-time continuum thought it was so great, with its hyphen, and its doubled vowels that normally weren't doubled in English, but anyone could see that Doofenshmirtz's happiness was far more important than anything else.

Perry the Platypus struggled more vigorously in response.

Heinz had his head bowed in concentration. "Space-time continuum... (I know that word!)"

Doofenshmirtz swallowed. He'd learnt a bit of English by this age, mostly from all those science documentaries narrated by that same British guy. He'd forgotten.

Heinz stared at him, then touched his own face. Perry the Platypus dropped to the ground, but Doofenshmirtz was too worried to care much. He didn't want his family to know who he was. It wouldn't make his plan any less likely to succeed, he just didn't want them to know. Things would get awkward, and he hated that.

Heinz looked down at the floor, then back at Doofenshmirtz. "You..." he said, in such a heavy Druelselstein accent that Doofenshmirtz nearly didn't understand him. "You are future."

He'd be glad when he learned enough English to make statements with less than five possible meanings. "No... No I'm not," said Doofenshmirtz lamely. He looked at his family. If he recalled correctly, none of them knew as much English as he did at that point. It looked like they hadn't understood all of that. He hoped not.

"I'm not from the future, honest," he added, more to fill the silence than because he thought his younger self would understand him. "I'm from 19... whatever year this is, just like everybody else." He smiled at his family, who looked at him solemnly.

Heinz kept staring at him, and Doofenshmirtz began to wish that he'd worn something more impressive. Maybe he should've rented a tux. He'd proposed to his ex-wife while wearing a tux. It always impressed people.

Perry the Platypus pulled on Doofenshmirtz's lab coat to get his attention, and handed him a sheet of paper.

Doofenshmirtz looked at it. "Huh? What? What is this?" He recognised the title from one of the scientific journals he subscribed to, but he hadn't read it all the way through. It had looked really dry and boring, and what was with that page full of equations, anyway? But, to humour Perry the Platypus, he read the rest of it, mumbling to himself as he did.

He finished, and the piece of paper slipped from his hands. Doofenshmirtz risked blowing up the Solar System every second day, and he didn't know what the Solar System had ever done for him anyway, but he almost never risked removing himself from existence. He'd heard that being erased from existence was very dark and cold, and unpleasant. It wasn't something he wanted to try for himself.

Perry the Platypus was looking at him reproachfully.

"What?" said Doofenshmirtz, annoyed. "Oh, you just think you're so smart, don't you, Perry the Platypus? Well..."

He trailed off. Heinz was holding the paper he'd just dropped in one hand, and an English-German dictionary in the other.

"(Give me that!)" said Doofenshmirtz, snatching the paper off him. With his luck, letting his younger self read it would blow up the entire galaxy. "Well, (I... I'd best be going. An immutable law of nature came up, and...)" He started to back out of the room. "(Goodbye!)" Another brilliant plan foiled by Perry the Platypus.

.

It wasn't until Doofenshmirtz left the house that he realised that somebody other than Perry the Platypus was following him. He turned.
"(I knew it was too good to be true,)" said Heinz. He kicked the dirt despondently. "(Nothing ever goes right for me.)"

"(Weren't you just saying...?)" began Doofenshmirtz, then realised that Heinz was looking at Perry the Platypus. He didn't know what his younger self liked so much about Perry the Platypus, but he was glad that he'd grown out of it.

Perry the Platypus patted Heinz on the shoulder, then looked at Doofenshmirtz nervously, like he was asking permission.

"Fine, go ahead, whatever," said Doofenshmirtz, with a flip of his hands. Perry the Platypus was too much of a goody-two-shoes to do him any damage.

"(Are you going back to the future now, Herr Schnabelsicht?)" said Heinz, sounding sad.

Perry the Platypus nodded. Then he seemed to realise something and looked up at Doofenshmirtz. At the same time, Doofenshmirtz remembered that he had control of the Time-Portalinator. He could just leave Perry the Platypus stuck in the past forever, while... was while the right word? Whatever, in any case, Doofenshmirtz could be rid of Perry the Platypus forever and make his younger self happy in the process. Everybody won, except the forces of good.

But... It'd feel so empty without him. A victory that didn't involve thwarting Perry the Platypus was barely a victory at all. Doofenshmirtz couldn't see himself tying up some new nemesis and telling them his evil schemes. It wouldn't feel right. "Come along, Perry the Platypus," he said.

Perry the Platypus turned away from the house, but he looked over his shoulder as he did it.

"(Wait!)" said Heinz. "(Herr Schnabelsicht... Perrytheplatypus.)"

For some reason, Perry the Platypus didn't look thrilled to be addressed by his real name, but he turned around.

Heinz stared at Perry for such a long time that Doofenshmirtz got uncomfortable and started whistling a song, remembered that he'd been taught it by the ocelots, and stopped abruptly. Finally, Heinz said "Auf Wiedersehen."

Perry the Platypus tipped his hat sadly.

"Uh..." said Doofenshmirtz. It was his younger self. He should be the one having the awkward goodbyes with him, not Perry the Platypus. "(Just between you and me,) don't... (don't take Karla to the puppet show when you're fifteen. It... It's just a bad idea.)" He patted his younger self on the shoulder awkwardly. "(Be evil,)" he said as a farewell.

Heinz's only response was a puzzled stare.

Once they were out of earshot, Doofenshmirtz said "(Oh, I hate that!)" Realising that he was still speaking German, he said "I mean, oh, I hate that! I've always hated it!"

Perry the Platypus looked at him curiously.

"Auf Wiedersehen," said Doofenshmirtz. Perry the Platypus seemed to be fluent in German now, so how could he not know this? "It doesn't mean farewell, it means see you later! You think just because it's formal, it means the same as in English, but no! It..."

He trailed off. Perry the Platypus was looking at him with one eyebrow raised.

Doofenshmirtz thought for a second, then realised what he probably meant. "Look, I don't care what it means in Germany." He folded his arms and looked away. "In Druelselstein, it always means see you later."

He looked back. If anything, Perry the Platypus looked even more sardonic. Apparently that wasn't it.

"What? What is it? It's true, you know. Everyone knows you say..." Doofenshmirtz trailed off. He'd known that for as long as he could remember. In fact, he'd always felt smug as a kid whenever somebody else used it incorrectly. So what...? "Th... That's weird..." Then he shrugged. He didn't feel annihilated from existence, so whatever his younger self had been implying, it wasn't a big deal. "Oh well!"

Perry the Platypus seemed to have something else on his mind now, but he wouldn't tell Doofenshmirtz what it was.

.

"But it was right here!"

It looked like Candace was as confused as Phineas and Ferb about the spatial-temporal anomaly that had erased their puppet show with talking puppets from existence, and after all that trouble she'd taken to show their mom, too.

"Candace..." began their mom, then changed her mind about whatever she was going to say, and just sighed. "Who wants snacks?"

"I do!" said Phineas. He knew that Ferb did too.

Before he could go inside, Phineas felt something headbutt him in the knee. He looked down. "Oh, there you are, Perry." He picked him up, and realised as he did that Perry was all tensed up. "Hey, what's the matter, boy?" Phineas turned Perry around so that he could see his face, but he looked the same as he always did.

Perry chattered, and put his front legs around Phineas's shoulders.

"Oh, you just want a hug!" said Phineas, and hugged him.

Perry slowly relaxed, and Phineas wondered what had happened to him to scare him so much. "It's okay. You're home now."

Perry chattered contentedly.