The story of a hum that has been keeping the people of Omagh awake for months. With the town exhausted and exasperated, local journalist Emmet McElhatton wants to get to the bottom of a mystery fast making headlines around the world. In the journalist's search for answers, he meets local repairman Jamie Ryan, who has started his own investigation into the elusive sound. Together, they make their way around Omagh and try to solve the mystery. They quickly realise, however, that they are up against much more than the hum itself. Rumours and conspiracies have taken hold of the town, leaving many either misinformed or weary of the hum and its coverage. In their search for the truth, how will Emmet and Jamie countenance the town's suspicions? Will they be able to fill the gap currently occupied by theories and rumours? And will they get Omagh a good night's sleep at last?