An esteemed piano tuner and repairer, Jacobo leads an apparently happy life with his wife, Helena. His serene existence is thrown into a state of confusion when insomnia creeps in, and pianos that previously repaired miraculously overnight remain unfixed. Jacobo plunges into paranoia and madness, hearing noises during the night and having ephemeral visions of a stranger roaming the house in a dressing gown. Helena reassuringly denies anything out of the ordinary, and suspiciously insists he is hallucinating. Is the life we think safe and secure true, or is there a second reality lurking?