A recent quantum model of consciousness proposes that neuronal clusters in the cortex switch from being an unconscious neural computer (when asleep) to a conscious quantum computer (when awake). The transition relies on feedback cooling, and is not unlike how a conductor becomes a superconductor when cooled. Here the model is explored in the context of sleepwalking, a peculiar but common phenomenon that has largely escaped philosophical attention. Based on several remarkable accounts, the case is made that sleepwalkers are truly philosophical zombies: they execute complex behaviour while remaining completely unconscious. They are phenomenal blanks, acting out pre-programmed routines governed by their neural computer. But when feedback cooling is active, the same neural circuits acquire macroscopic quantum coherence, and the sleepwalker awakes and becomes conscious. The claim under test is that if zombies exist, materialism must be false, for there is something – the mind – over and above the body.