Detective Constable Henry Campion turns lone avenger when his childhood friend and colleague DC Fred Jordan is shot dead by a gangster who is spared the death sentence. And Campion is convinced there were two killers. To try to catch the second, Campion goes undercover as a spiv in a King's Cross nightclub, the Full Moon.
But Campion's adventures at the Full Moon draw him deeper into gangland, and closer to the woman of his dreams - his dead friend's widow . . .
But is it love, or is Anne Jordan using Campion for her own ends?