140 decibels is the limit of human tolerance beyond which sound becomes unbearable. But Thomas is already far past this threshold.

For a year, Thomas has been suffering from hyperacusis, a hearing disorder that makes him hypersensitive to most noises. To protect himself, Thomas has isolated himself from the world. One summer, his family swaps houses with another, and to his amazement, he discovers that the owner of his bedroom has left him a full-scale treasure hunt. From one riddle to another, Thomas advances, hesitates, stumbles: embarking on this adventure, he knows the risks but not what he will find at the end.