Ep 9. One Good Scare Ought to Do It! (Parts 1 & 2)

In Phineas and Ferb season 1 episode 9, titled "One Good Scare Ought to Do It! (Parts 1 & 2)," the step-brothers Phineas and Ferb come up with a plan to help their friend and neighbor Isabella win a scout troop's annual scare competition. The competition seems to be more about scaring other kids than actually being scared, but Isabella is still determined to win.

To create the ultimate scare, Phineas and Ferb build a haunted house loaded with high-tech gadgets and gags. Meanwhile, their sister Candace tries to bust them to their mom for their latest invention, but as usual, she ends up failing.

As the day of the competition approaches, Isabella is having a hard time scaring anyone. However, they soon realize that someone else is behind the lack of scares -- a mysterious figure named the "ghost of the haunted house." The ghost is revealed to be a boy named Albert who used to live in the neighborhood and died in the haunted house years ago. He's been haunting it ever since, preventing anyone from using it.

Phineas and Ferb are undeterred by this revelation and continue with their plan, determined to help Isabella win the competition. They team up with Albert and use his ghostly powers to add even more scares to the haunted house. It all culminates in a thrilling and hilarious scare-off at the competition, where Isabella's troop comes out victorious.

In the end, Candace still fails to bust her brothers, but she does end up getting scared herself -- by the real ghost of the haunted house, who turns out to be very friendly after all.

Overall, "One Good Scare Ought to Do It! (Parts 1 & 2)" is a fun and spooky adventure that showcases Phineas and Ferb's inventive spirit and Isabella's determination to achieve her goals. With plenty of laughs and surprises along the way, it's a must-watch episode for fans of the show.