Bollo, the oldest and most respected gorilla at the Zoo-niverse, is gravely ill. Bob Fossil persuades Howard to dress in an ape suit, replacing Bollo, so that he can continue accepting sponsorship money for the gorilla. Everything's going smoothly until the Grim Reaper arrives and mistakenly takes Howard to Ape Hell instead. Vince, guided by Naboo, sets off to rescue Howard, and on the way meets Mr Susan, caretaker of the Mirror World. Howard and Vince run into trouble when they encounter the Ape of Death who is plagued by problem hair.