Phineas and Ferb - Season 2 Episode 6 -

In "Day of the Living Gelatin", the boys make a gelatin dessert, but, unbeknownst to them, Dr. Doofenshmirtz brings the gelatin to life. In "Elementary, My Dear Stacy", Stacy accompanies the family on a trip to London, where she and Candace try again to bust the latter's brothers, in the style of Sherlock Holmes.