Ep 15. Tri-Stone Area / Doof Dynasty

In Phineas and Ferb season 3 episode 15, titled "Tri-Stone Area / Doof Dynasty," the gang finds themselves transported back in time to the prehistoric era. The first half of the episode, "Tri-Stone Area," sees Phineas, Ferb, Isabella, Buford, and Baljeet navigating life in the Stone Age while still trying to come up with their usual larger-than-life projects.

Meanwhile, Perry the Platypus finds himself on a mission to stop Dr. Doofenshmirtz, who has also time-traveled back to the prehistoric era, from creating stone-age technology that could permanently alter the course of history. Perry must navigate a world full of saber-toothed tigers, angry volcanoes, and even a giant sea monster in his quest to stop Doofenshmirtz from achieving his evil goals.

The second half of the episode, "Doof Dynasty," takes place in ancient China, where Dr. Doofenshmirtz has become emperor and is ruling with an iron fist. This time, Perry teams up with a local rebellion to overthrow Doofenshmirtz and restore peace to the land.

As usual, the show's trademark humor and inventive storylines are on full display in this episode. Fans of the series will love seeing their favorite characters in these new and exciting settings, while newcomers will be immediately drawn in by the show's unique blend of humor, heart, and creativity. Whether you're a fan of time travel stories, historical fiction, or just good old-fashioned slapstick comedy, "Tri-Stone Area / Doof Dynasty" has something for everyone.