User blog comment:Anomymous Writes/Crossover with Phineas and Ferb/@comment-188.25.223.239-20130403075249

I know it's crazy but I've been thinking of this idea for an hour long episode:

Phineas,Ferb,Candace and Isabella visit Jeremy's friend Soos in Gravity Falls,while Doofensmirtz allies himself with Gideon to take over Gravity Falls.

Soos introduces them to Dipper,Mabel and Stan.

Mabel develops a crush on Phineas,and after annoying Dipper about it,Dipper convices Phineas to go on a date with Mabel.When Isabella finds out,she feels neglected,while when Gideon does he and Doof build a giant robot to ruin the date.

Dipper,Ferb and Stan start building a huge surprise for Phineas,while Perry manages to stop Gideon and Doof,however Doof escapes.

After this,Waddles and Perry become friends,and Waddles joins OWCA.

Meanwhile,Doof finds some words written at the arcade and manages to summon Rumble.He plans to use it to destroy Perry and Waddles.

Phineas and Mabel go on another date,but when Mabel is constantly flirting at him,Phineas confesses his true feelings for Isabella and leaves.Mabel is heart-broken.

Meanwhile,Doof finds out that Phineas is Perry's owner,and tries to kill him.He sends Rumble,but,working together,Phineas,Dipper and their friends stop Doof and defeat Rumble.

Candace keeps trying to convince Sheriff Blubws and Deputy Durland to quit their foolish habits and to help her bust her brothers,however,she can't get anywhere with that.

During the fight with Doof,Phineas almost falls into the Bottomless Pit,however Isabella catches him.The two confess their ture feelings to each other and start their romantic relationship.Near the end,Ferb asks Mabel out and she says yes.Both couples enjoy their dates at the Mystery Shack,while Stan unveils the surprise:a real-size replica of the Statue of Liberty.

At the end,Candace sees the statue,but,when Jeremy arrives,they have their own date too.Then,Phineas,Ferb,Isabella,Candace,Jeremy and Perry say goodbye to their friends,while a mysterious figure looks at them from the bushes...