Karl discusses what his doppelganger would be like. Ricky gives Karl a riddle. Karl and Stephen say what they do not like about Ricky's cat. Stephen discusses his holiday in Rio, where he went for Carnival.

Ricky gives Karl some animal facts. Karl ponders the question of whether you control your brain, or your brain controls you. From Karl's diary we investigate the curious case of the invisible Chinese man, why blind people have affairs, the feasibility and usefulness of putting a mirror on the Moon, and birthdays.