The Blur Of Blue

This is the third episode of Phineas and Ferb Forever. It is the first crossover in the show. It crosses over time and space to Sonic The Hedgehog's world.

Summary
Phineas, Ferb, and Gretchen are messing with Phineas's new ExtraPhone. Phineas shows them a brand new, dimension crossover app. He draws a circle and a strange world appears. Candace is running through when she trips and falls into the portal. Seeing this, Phineas, Ferb, and Gretchen jump in after her. Candace is laying on her back, looking at the place around her. "CHECKERBOARD GROUND? IM TELLING MOM!" she yells. Phineas helps her up and they feel a sudden rush as a blue blur comes by. "What was THAT?" Gretchen exclaims as a flying yellow fox with TWO TAILS comes by. Phineas and Ferb run after the strange creatures.

Back on earth, Perry finds the portal and jumps in. Meanwhile Doofenshmirtz locates Perry, sneaks into the backyard, and jumps into the portal also, closing it.

Phineas and Ferb finally catch up with the blue creature. It is a hedgehog standing on two feet, he has red shoes and quills. "Say, humans? Haven't seen them in a long time. Nice to meet you." Sonic said, shaknig Phineas and Ferb's hand. "Wait a minute, where's Gretchen?" Phineas asks, then looking down at his hands and feet, he sees he has white gloves, blue shoes, and a black gleaming nose, he also has red quills. "Well, this isn't the first weird thing that happened today." he exclaims, he is a hedgehog. He also notices that Ferb is gone. "Could you help me find my brother Ferb?" Phineas asks Sonic.

Meanwhile, Doofenshmirtz finds Eggman and they team up to stop Perry, they trap him in an Egg Prison and Doofenshmirtz ponders how they will get back.

Back to Phineas and Sonic, Candace has also disappeared. They rush to Eggman's base where Phineas finds a green hedgehog, Ferb. And two orange hedgehogs, Candace and Gretchen. Candace complains about being a 'smelly sharp animal'. Sonic gets angry for this, and busts open the door to the base. They make it to Eggman's room, where Perry has escaped and Eggman and Doofenshmirtz are in a big fight. Phineas grabs Perry and says goodbye to Sonic, then grabs his ExtraPhone and creates another portal, which Doofenshmirtz follows them into, back home.

Songs
In This Crazy World

Trivia
The line "Hey, where's Gretchen?" is like "Hey, where's Perry?"

This is the first crossover in the show.