Ep 20. What Do It Do? / Atlantis

Phineas and Ferb season 2 episode 20 is titled "What Do It Do? / Atlantis". The episode consists of two separate storylines, with equal importance given to both.

The first storyline, "What Do It Do?", revolves around Phineas and Ferb's latest invention, the "What-Does-This-Do-Inator", which they believe will be able to solve the age-old question of what particular objects do. However, things quickly go awry when the invention becomes uncontrollable and begins causing chaos throughout Danville. Meanwhile, Perry the Platypus must once again fight against his nemesis, Dr. Doofenshmirtz, who plans to use the chaos caused by the invention to take over the Tri-State Area.

The second storyline, "Atlantis", follows Candace as she tries to convince her brothers to take her on their latest adventure, which involves finding the lost city of Atlantis. However, when they actually find Atlantis, they discover that the city has been modernized and turned into a tourist destination, much to their disappointment. Meanwhile, Dr. Doofenshmirtz attempts to use an Atlantean artifact to take over the world.

Throughout the episode, there are numerous musical numbers and comedic moments, as well as appearances by various recurring characters such as Baljeet and Isabella. Both storylines ultimately converge in a satisfying and exciting conclusion that leaves viewers eager for more. Overall, "What Do It Do? / Atlantis" is a fun and engaging episode of Phineas and Ferb that showcases the show's trademark blend of humor, creativity, and heart.