It was an incredibly hot day, and yet the Flynn-Fletcher boys were outside, sitting underneath their back tree. Well, sitting was a generous term, as Phineas and Ferb were more slumped against the tree while Perry laid out spread-eagle on the grass in exhaustion, though perhaps that could be accredited towards the nature of his work than the hotness of the temperature. Perry wasn't entirely sure, but surely the heat was draining him too as he watched a bird literally burst into flames as it flew too close to the sun, like some sort of weird Icarus reference.

Over the radio came an announcement, "This is stanky Dog comin' to you on the hottest day of the summer! Unless you live at the beach, I say take it easy and do nothin' today. Yup, just find yourself a shady tree, and maybe an aquatic mammal of some sort, and blow the whole day off."

Who on earth would have an aquatic mammal next to a shady tree?

"Come on, Ferb. If we let a little heat stop us from having the best day ever, then the morning DJs win," Phineas stood up. Perry had no idea what Phineas suddenly had against DJs, but then again he wasn't too interested to find out. Too bad Phineas didn't care that Perry just wanted to lay on the ground, as he added enthusiastically, "Come on, Perry!"

Groaning, Perry lifted himself off the ground before Phineas got any ideas about helping him up. Thankfully, all Phineas and Ferb wanted him to help them with at that moment was to drag their sandbox out along with a few bags of sand. After that the boys then changed into swim trunks, so reluctantly Perry decided it was probably time for him to get ready for work.

Would it be too unprofessional to show up to his mission in swim trunks? Perry sighed as he decided yes, it would be, and changed into his significantly warmer outfit. This time, however, Perry didn't put his hat on just yet.

As he stepped back outside, he could hear Mom talking to Phineas and Ferb, "Ooh, boy it's hot today! So, what are you up to?"

Phineas answered, "We're making our own beach, right here in the backyard." Ahh, it sounded so heavenly to Perry. Maybe if he was lucky it might still somewhat be there when he got back.

"Oh, how cute," Mom said. "Well, I'm off for my spa day. You boys behave yourselves and don't bother your father. He's finally cleaning the basement." The basement also sounded like a great, cool place to be on this sweltering day.

"Bye, Mom!" Candace said. "Yes! You heard her. We can't bug dad which makes me in charge… by default." Perry wasn't so sure how she worked that out, but he was hardly going to go over there and disagree with her. She paused, and then added, "Carry on."

"We're gonna need more sand," Phineas stated. "Hey, where's Perry?"

Well, that meant it was time to go to work. Perry walked over to an unusually large mushroom in another section of the backyard and opened it up, revealing it as an entrance to his lair. Jumping in, Perry landed in his lair through the tube and walked over to another tube that dispensed his fedora. Ready to go, Perry sat in his chair and pushed a button on his controls.

"Good morning, Agent P," Monogram greeted on the screen. "Lawn gnomes across the Tri-State Area are disappearing, leaving thousands of gardens unprotected from the evils of black magic. We suspect Doofenshmirtz. Get right on it."

Perry saluted and then headed back up to the surface. Now, he just had to figure out how to figure out where Doofenshmirtz was and where he had the lawn gnomes…

(SLIGHTLY LATER)

From a relatively hidden place in the backyard, Perry watched mournfully as Phineas and Ferb finished their backyard beach that he couldn't partake in. After attempting to think of ways to locate Doofenshmirtz and the gnomes, he decided that the best course of action was to disguise himself as a lawn gnome so it would suck him up and take him straight to the source. Admittedly, he was bigger than most gnomes, but he figured if he happened to get stuck, then it would stop Doof's plan anyway.

So now Perry was standing out in the hot sunny backyard in most of his agent outfit and a fake beard and a pointy hat rather than getting to enjoy a nice swim. He hoped wherever this would take him was cool, at least.

It was after Stacy and Jenny showed up to the beach that Perry finally felt the ground underneath shake some before sucking him completely through a tube. Aha, so he wasn't too big for it! Though as it led to a conveyor belt, the opening was a little too short for him, so he had to duck a little bit. Thankfully, not only had he located the lawn gnomes but he'd also located Doofenshmirtz at the same time as he could hear him giggling to himself.

"Yes, yes! Just look at my bounty of gnome riches!" Doof then saw Perry disguised as a lawn gnome and grabbed by the shoulders, remarking, "Oh, this is a strange one." Perry promptly punched him in the face. "Wait, who are you?" Perry quickly removed his fake beard and pointy hat, leaving him hatless. "Some guy?" Ah, that's right, Doof could never recognize him without his fedora, so Perry put it on. "PERRY THE PLATYPUS?!" Doofenshmirtz pointed at him, and then held out a remote. "You are mine now!"

Behind him, Perry turned as he heard what sounded like a garage door opening. Sure enough, that's what it was, so he put his hands on his hips.

"Oh, no, wait, wait, wait," Doof said. "That was the garage door opener. You are mine now!" He pressed another remote button, which activated the large monitor behind him. "And that was the TV remote. I've got to start labeling these things. Aha! YOU ARE MINE NOW!"

This time when Doof pressed the button, a cage actually fell on top of Perry. It looked like a giant version of a pet carrier, which Perry thought was kind of an odd theme to go with, and the gate barely budged when he grasped ahold of the bars.

Doof laughed maniacally, "Ahahahahahaha, finally I will rid myself of you! But first," he then grabbed another remote out and pointed it towards the monitor, and Perry couldn't tell which one it was, "Turn your attention to the giant screen and…" when he pressed the remote, the garage door closed. "Hmm, maybe I need to turn the cable on first?"

As he waited for Doof to find the correct remote, Perry wondered how the backyard beach party was going.

(LATER)

While Perry did feel bad about Doofenshmirtz being forced into being the family lawn gnome when he was a child, and he really did feel bad especially after briefly experiencing himself having to disguise as a lawn gnome and stand outside on one of the hottest days of the year, that didn't stop him from pummeling the scientist when he pressed the wrong remote yet again and released Perry.

What he hadn't exactly meant to do, however, was sending Doof into the lever on BLOW so that all the gnomes went up to who knows where. Oh well, he hoped that it wasn't too destructive that the gnomes were shooting back up to the surface.

He also hadn't planned on when he hit Doof that he would send him into the lever in the opposite direction, SUCK. They both watched concernedly as the tube sucked in too much of something… WATER? Perry didn't think they would be that close to the harbor, so it must have been the backyard beach.

As he was absolutely drenched in the cool torrent of water, Perry managed to swim in an upward direction while also shedding his clothes and stuffing them into his bigger-on-the-inside fedora. By the time the water drained down the cave completely, he saw that he grasped onto the side of the hole only a few feet from the surface.

As he climbed up those last few feet, he saw that he was completely surrounded by people watching him. He winced inside; that was not his best plan to just crawl out of a hole that had likely just sucked all the water in the region. Somehow, he had stripped mostly out of his clothes into his swim trunks, so he was at least dressed appropriately.

"Oh, there you are, Perry!" Phineas said.

"Hey," Perry said in reply, walking over to him and Ferb.

"Well, everybody, looks like that's all for today!" Phineas announced to the bystanders, waving.

As Perry, Phineas, Ferb, and Isabella walked back to the actual backyard, everyone else was chanting, "Phineas and Ferb! Phineas and Ferb! Phineas and Ferb!" until the fence rotated back to block the view of them.

"That was great!" Phineas declared as Mom walked into the yard.

"Hey, boys," she greeted.

"Hey, Mom!" Phineas said as all three boys waved.

"So how was your day at the beach?" Mom asked. Perry shrugged; the only bit of swimming he had done was getting out of the hole.

Candace came running into the yard, "Wait, wait! My kingdom, my Jeremy, it was all so beautiful!" she then got right into Phineas's face and desperately asked, "What have you done to my paradise?!"

Well, technically, it was Perry who had done something to it and not Phineas, but even he felt like she was being a bit more dramatic about it than usual.

Mom grabbed her by the shoulders gently and said, "Candace, honey, I think it's time to get you out of the sun for a little while." With a concerned face, Isabella helped Mom get Candace back inside.

"I think she had fun!" Phineas told Ferb and Perry.

Well, Perry thought it was the perfect time for a nap. He headed over to the tree and turned on the radio, which was playing the end of "If Summer Only Lasted a Day". Lying down on the grass, Perry closed his eyes and listened as his brothers joined him by the tree, sitting down.

Over the radio the DJ's voice came through, "Stanky Dog here with a special shout-out to my two new pals, Phineas and Ferb, for hosting a beach party that was hot, hot, hot. And speaking of hot, slather on the sunscreen, listeners, 'cause tomorrow's weather calls for another scorcher." Well, at least that likely resolved whatever Phineas had against morning DJs.

"With a slight chance of scattered lawn gnomes," Ferb added, to which Phineas laughed. Perry opened his eyes for a little bit and realized he could see a few gnomes stuck in the roof. Oh well, he'd deal with the fact he'd caused Gnome-aggedon later, for now it was onto naps and sweet dreams.

Perry the Teenage Spy Theme Song

He's a semi-dramatic, teenage boy of action!

He's a teal-haired secret agent who'll never flinch from a fray

He's got more than just mad skill

But not a beaver tail or a bill

And the women swoon whenever they hear him say

Hey

He's Perry! Perry the Platypus!

(Oh, wait a second!)

He's Perry! Perry the Teenage Spy!

Perry! Agent P!

A/N: If you want to hear this version of the Perry the Platypus theme, I recorded a low-effort acoustic version, and I linked it in the end notes for this chapter on AO3. I don't recommend trying to sing the phrase "teal-haired secret agent" as that took several takes lol. I may have to post my outtakes later.