A detective desperate for revenge. A hitwoman with one last job. A killer with both on his list.Detective Matt Jackson's beloved wife, Polly, is the latest victim of a serial killer - Neon - who displays his victims amongst snaking neon lights.Suicidal but unable to kill himself, he hires someone to finish the job. But on the night of his planned murder he makes a breakthrough in the Neon case and offers his assassin, Iris, an irresistible opportunity: help Jackson find and kill Neon in return for his entire estate.What follows is a thrilling game of cat-and-mouse between detective, assassin and serial killer. But when Jackson discovers it's not a coincidence that their paths have crossed, he begins to question who the real target has been all along...