Stephen reads an e-mail from a listener who asks, "If Karl could spend a day with his doppelganger, what would he do with him?" Ricky poses a logic riddle for Karl to solve. Entries from Karl's diary include: why he doesn't understand art, why his aunt wants to cover her backyard with Astroturf and why he doesn't like Ricky's cat. Finally, Stephen shares anecdotes from his trip to Rio de Janeiro.