When the Ulster Sovereign docks in Liverpool, one of its passengers from Belfast is missing. Jack Penrose had everything to live for, but his body is later picked up by fishermen off the Irish coast. Dismissing any suggestion of foul play, the coroner’s verdict is suicide. But why? In desperation, Jack’s partner calls Chief-Inspector French back to Northern Ireland, where he guides Superintendent Rainey and Sergeant McClung through a maze of startling developments and nebulous clues to a thrilling solution to a very unusual crime.