"I see." Shredder said. "So, there is another Earth in another dimension?" "Yes, the one who is known as the Shredder is correct." The Kraang answered. "Hmm." The Shredder pondered. "Were there any people who is currently taking control over the Earth?" "No, the one who is known as the Shredder." The Kraang replied. "But, there is one who is known as Dr Heinz Doofenshmirtz who is currently trying to take over what is currently known as the Tri State Area. He has an enemy who is known as Perry the Platypus."

"Interesting." The Shredder said. "The turtles have interfered with my plans long enough. I can gain control of the dimension and gain my own mutant army. That way, nothing will stop my plans from taking control of the world and taking Hamato Yoshi down." The Shredder laughed under his breath as he thought of his seemingly foolproof plan.

"They were your enemies?" Major Monogram asked the turtles. "Yes, sir. They are trying to take over OUR world!" Leo stated.
"Now, they are trying to take control of both worlds!" "We can't just stand by and do nothing!" Phineas said. "We must take action now!" "Yeah, but how do we do that?" Buford asked. Just then, Perry took his platypus foot-shaped locket and passed it to Phineas. Phineas remembered what it does and immediately understood. Just then, Major Monogram came back with more reports. "Agent P, there are more reports sent by the other agents, informing us that someone who is known as the Shredder has passed into our dimension." "What? The Shredder?" The turtles gasped in horror.

"You know him? Who is he?" Phineas asked. "The Shredder is our biggest enemy." Leo explained. "He and our master, who is also known as Hamato Yoshi, used to be brothers, but they are now enemies." "He is a high-level assassin. We have tried to defeat him, but we failed each time. We barely escaped with the skin of our shells." "Hmm, he sounds like he is a hard nut to crack." Phineas pondered. "But luckily, I think we got the right tools to stop them." "Huh?" The turtles wondered. "He is an assassin and is very dangerous. Are you guys sure you won't get killed? Perhaps..." "Don't worry, we won't." Phineas said confidently. The turtles widen their eyes as Perry switched his big screened monitor to Emergency Alert Level Alpha Red mode. "Please insert the key." The monitor indicated.

Phineas immediately put the locket onto the keypad. "Phineas and Ferb, this message is top-secret, for your ears only." "For your ears? What the shell?" "SHHHH!" Donnie shushed Raph. "If you are hearing this, the Tri State Area is at Emergency Alert Level Alpha Red. Agent P needs your help." "How does he know we'll know what to do?" Despite remembering about their interdimension adventure, Phineas asked that question anyways. "He knows you will know what to do. He also knows that you two are the only ones capable of helping him, because you two are the only ones capable of creating these." As the message has finished relaying, a giant door behind them was opened. The turtles and children and Agent P turned towards the door.

"Auto-Scan Replication initiated." The inventions that Phineas and Ferb built all summer were being replicated and displayed. Phineas and Ferb and the other children beamed with pride as they remembered the adventure that they had while using the inventions. The turtles looked on in amazement.

"Woah..." Donnie said in awe. "Amazing!" "Incredible!" "Wow, this, is, AWESOME!" Mikey can't help but shouted excitedly. "You guys really built all this? I am not doubting your abilities to invent anymore!" Phineas and Ferb beamed. "Thank Perry, he replicated all those inventions." Everyone smiled at him while Perry blushed a bit. "Isabella, can you call Stacy and Candace?" Phineas immediately instructed. "And Buford and Baljeet, can you call Irving and everyone else?" "Of course." Everyone of the gang went off. "Perry, can you get the other agents? I think we need all the help we can get." Perry gave them a salute before rushing off. "What are we supposed to do?" Leo asked. "You did mention you have a master right?" Phineas asked. "Why don't we finish the portal and get help from your dimension?" "Uh...ok." Though the turtles are a bit uneasy about Master Splinter's reaction if he sees the children, they knew they need all the help they can all get. "Ok then. Ferb! Let's go help them finish the portal!" Ferb blew a key in response.