Whilst devoting his life to his work, Will Wagstaffe, also known as Staffe to his colleagues, battles personal demons. He's haunted by the unresolved murder of his parents, which affects both his private and professional life including his on-off romance with sometimes girlfriend, Sylvie. His closest relationship is with his sister Juliette, and young nephew Harry, who stays with him when Juliette has troubles with her boyfriend.

With no parents and no significant partner of his own, Juliette and Harry mean everything to Staffe. Determined and tenacious, Wagstaffe is an exceptionally good police officer, in spite of the fact he's been known for pushing the boundaries of what's considered acceptable policing.