Concerned about the safety of a treehouse Calvin's building for Grover, Dave recruits Marty to supervise covertly. Also, an innocent mistake on Malcolm's part leads to a heated bake-off between Tina and Gemma.

Dave earns Calvin's respect when he thwarts a robbery at the barbershop, until the recognition goes to his head and he starts exaggerating the truth. Also, Marty invites an anxious Gemma to give his new stress-busting hobby a try.