Malcolm Turner has suffered from what he thought was tinnitus all his life. Of late, the episodes make him feel like his brain is bleeding, depriving him of sleep and working away at his already faltering marriage and stale career. Little hope remains. Desperation leads him to a chat room and a group of similar folks who call themselves 'The Undertones.' After a series of shared experiences, the group contemplate that this bane of their lives may not be a curse but a gift—free-thinking radicals picking up on something other than the grind of the machine. As sinister events begin to unfold around the world, 'The Undertones' become convinced that this noise in their ears might hold the key to these horrors. Malcolm has already tasted grief, but the stakes are as high as they come this time. Will he get answers before his world comes tumbling down?