The Justice Brigade was fighting the Super Crew. The Archer shot four arrows at the Justice Brigade, but someone's Laser Vision destroyed them. The Justice Brigade looked up and saw Krypto, the Superdog. Chip then electrified Cordelia, so Lance tried taking him out. Ace the Bathound threw a Batrope at him, but Lance cut it with his dragon claws. The Justice Brigade watched The Justice League's pets in action and were amazed by them. Kitty Hawk then grabbed The Archer's bow and threw it up. Mark then set it on fire while Keith hosed Lance's mouth. Wonder Pig then socked Lance while Merton ran fast up to Serpent and knocked him towards Lance. Once Lance landed on Serpent, he changed back into a human. When the police came, they took the Super Crew to jail. Then Ace the Bathound barked at something in an alley. The Justice Brigade and The League of Super Pets saw cats holding ray guns and flying in hovercrafts. Sungirl said, "This is strange." Two cats shot their laser beams, nailed Ace and Mark, and turned them into cats. Heatgirl said, "They got Ace and Mark." Iceboy said, "Time to go." The cats tried nailing the other heroes, but Krypto grabbed Wonder Pig and flew away; Metron ran away fast, Kitty Hawk grabbed Keith and flew away, and the Justice Brigade followed them. The cats in the hovercrafts chased after them and tried shooting them out of the sky.
Once they were somewhere safe, they lost the cats and took The League of Super Pets back to their house. Sungirl took them to her lab and instructed them to stand on the X, while her team put on safety goggles. Sungirl then activated her machine, allowing The League of Super Pets to speak English. Iceboy said, "Ok, now that you can speak our language, maybe you can tell us what's happening." Chip said, "We came from Gotham City to find you four. Our owners have been captured by a talking cat named Mr. Boots. He's holding them captive somewhere in the world, but we don't know where. Sungirl then typed on her computer and located the Batmobile to find Batman. Sungirl said, "I've located The Batmobile in Vermont." Chip said, "I bet that's where we'll find Boots' hideout and hopefully The Justice League." Wonder Pig said, "But how do we get there without getting attacked by Boots' cat army?" Heatgirl thought about it and said, "I guess we'll just have to be on our guard."
The Justice Brigade and The League of Super Pets hopped aboard The Justice Brigade's jet and flew to Vermont. Once they arrived, they disembarked from their jet. Heatgirl then took a pair of binoculars and saw cats turning everybody and everything into cats. Heatgirl said, "This must be the place." The Justice Brigade and The League of Super Pets followed one of Mr. Boots' cats to his hideout. Once they arrived, Mr. Boots was watching how things were going. Mr. Boots said, "Excellent. Soon, the whole world will be cats." The alarm in Mr. Boots' hideout went off, and he checked it. Mr. Boots said, "Looks like we have some uninvited guests." Mr. Boots snapped his fingers, and his cat henchmen arrived. Mr. Boots said, "Take those guys out even if you have to turn them into cats because in 1 hour, the entire Justice League is going kaboom, and I don't want anyone stopping the countdown."
Mr. Boots' cat henchmen flew out of his hideout and to where The Justice League and The League of Super Pets were. Sungirl said, "Ok, everybody, fight." One cat tried blasting Krypto with his cat blaster, but he dodged the attack by flying and then melted his cat blaster with his heat vision. Merton then ran super fast by the cats and took them out. While fighting, Mr. Boots watched the whole thing and wondered who would win. One of the cats then blasted Kitty Hawk with one of their cat blasters, missed, and turned a tree into a whole bunch of cats. Kitty Hawk hit the cat blaster out of his hand, and Heatgirl caught it and melted it. Aquaboy then took the water out of Mr. Boots' plants and launched the water at the cats, short-circuiting their weapons and washing them back to Mr. Boots' lair. Mr. Boots then arrived in his hovercraft, blasted Aquaboy, Chip, and Keith with his cat blasters, and turned them into cats. Sungirl said, "He got Aquaboy." Krypto said, "He also got Chip and Keith." Mr. Paws then flew back to his lair, and the remaining heroes followed him. Krypto carried Wonder Pig, Kitty Hawk carried Merton while they flew, and the Justice Brigade followed.
The remaining heroes then reached Mr. Boots' lair and snuck in. Once inside, they saw cat guards marching everywhere with cat blasters. They followed the cat guards to Mr. Boots' room and saw him leaving. Merton hurried inside before the door closed, letting his team and The Justice Brigade inside. Once they got inside Mr. Boots' laboratory, they saw a group of cats working on his doomsday device, and the Justice League was captured with 30 minutes left on the clock. Sungirl said, "Super Pets, you stop the doomsday device. Heatgirl and Iceboy, you guys free The Justice League; I'll try to stop the clock before The Justice League is destroyed." Iceboy said, "Ok, but hurry, only 28 minutes left." Then, a yarn ball dropped on them, and they got caught.
Mr. Boots then trapped Krypto, Wonder Pig, Merton, and Kitty Hawk in cages that were designed to prevent them from using their powers. He then hung the Justice Brigade in yarn over spinning blades from the ceiling. Mr. Boots then flew to the Justice Brigade and told them what would happen. Mr. Boots said, "In 27 minutes, the entire Justice League is going to be destroyed, and even if they manage to escape before this place explodes, they'll never stop my doomsday device set to go off in the same amount of time. So, in 26 minutes, I'll turn the world into cats, and everyone and everything will work for me. No more dogs to chase me and no more people to bother me. Especially animal control, which would take me to the shelter. And you won't be able to stop me because my cats will drop you into that pit of spinning blades. Have fun. Ha ha ha."
Mr. Boots left, and the Justice Brigade saw they had only 23 minutes to stop him. Heatgirl said, "Krypto." Heatgirl blasted Krypto's cage with her Heat Vision and destroyed it. Then he flew up to the Justice Brigade when they fell and saved them in time. Sungirl said, "22 minutes left. I'll stop the kaboom; you guys try to stop that doomsday device." Krypto, Heatgirl, and Iceboy hurried out of Mr. Boots' lair and saw him setting up his doomsday device; Mr. Boots then pushed the button and said, "There. In 20 minutes, kaboom, cat world." Iceboy said, "Hey, fur ball, surprise." Iceboy kicked Mr. Boots, and he got ready to fight them. Mr. Boots said, "You again. No matter." Mr. Boots tried blasting them with his cat laser, but he missed."
Meanwhile, Sungirl pulled a lever on Mr. Boots' control panel, stopping the clock at 17 minutes. Sungirl said, "Ok, one timer down, one to go." Sungirl then set The Justice League and their remaining pets free, and they flew to where Mr. Boots was. While they did so, Iceboy kicked Mr. Boots' cat ray out of his hands, and Heatgirl destroyed it. Iceboy said, "Heatgirl, the doomsday device." Wonder Woman said, "Don't worry, we'll handle it." Sungirl said, "And we'll take care of whiskers." The Justice League saw that there were only 13 minutes left. Mr. Boots then brought out another cat blaster and hit Krypto with it. Superman said, "Krypto!" He then aimed at Wonder Pig, missed, and hit Merton instead. Flash said, "Merton!" Kitty Hawk got blasted next. Hawk Girl said, "Kitty Hawk!" Sungirl and Hetagirl got blasted next. Iceboy said, "Sungirl, Heatgirl!" Superman got blasted next. Iceboy said, "Superman!" Mr. Boots hit Flash next, and Green Lantern said, "Flash!" Cyborg was the last to get turned into a cat, and Hawk Girl said, "He got Cyborg!"
The only ones left were Wonder Pig, Iceboy, Green Lantern, Wonder Woman, Batman, Aquaman, and Hawk Girl. Mr. Boots kept trying to turn them into cats, just as he had their friends, and The Justice League stopped his doomsday device with six minutes left. Then, Iceboy froze Mr. Boots in solid ice and restarted the clock on his doomsday device. Wonder Woman said, "What are you doing?" Iceboy said, "Trust me." Iceboy tampered with the wires on Mr. Boots' doomsday device for a while and rewired it. Once the clock ran out. It sent out a signal, turning everybody and everything into cats. But then Iceboy's tampering kicked in, which reversed the effect and turned everybody and everything back into themselves. Mr. Boots said, "What happened?" Iceboy said, "I reversed the polarity of your doomsday device. So when it took effect, it reversed everything you did in the process."
Once the police arrived, they took Mr. Boots to the animal control center in Vermont and locked him up there. The Justice Brigade, The Justice League, and The League of Super Pets all slapped hands and congratulated each other on a job well done. Batman said, "Good work, Justice Brigade. We may be calling on you guys again soon." Sungirl said, "Looking forward to it. The language beam I hit your pets with should wear off in a few hours." Wonder Woman said, "Thanks." The Justice League then grabbed their pets, got in their ship, and flew back to their watch tower in space.
The End