Seán Galvin isn’t like the other children. While they play and laugh and keep on growing up, Seán doesn’t. Instead he does stuff to things. Things like cats and dogs. Bad stuff.

Seán has only one friend, the nameless narrator who tells their story. Their young lives revolve around sport and school. That is until Seán finally does something appalling and the boys have no choice but to tell someone. Someone older. Someone they should be able to trust. What they uncover is a secret far more awful than anything Seán is capable of: they witness a murder. Or do they? Because of their previous behavior, no-one believes them. They begin to unravel a rather sinister series of links between people whom they thought they could trust and the person who they saw committing the crime. Their little rural town becomes a place of cold skepticism and barely-hidden conspiracy. But is there really a conspiracy?

Accused of being 'freaks', they become more and more isolated, and even Seán starts doubting. But the novel’s increasingly unhinged narrator embarks on a mission to prove that they saw what they saw and his obsession will see their friendship tested to its limits and their lives changed forever.