When the Turtles are reunited with Casey and April, it's smiles all around ... until it becomes clear that Casey's being brainwashed by his new martial arts instructor, Master Khan, a devoted Foot operative. The Turtles must save Casey (and themselves) from this deadly Foot fanatic.

Casey and Raph head to Chinatown to find an engagement ring for April. They find one, all right. Too bad it has dark, transformational powers. Powers that are of interest to Hun and the Purple Dragons as well.