The Gelignite Gang — John Creasey

There has been a succession of jewelry robberies whose trademark -- safes blown open by explosive gelignite -- links them in Scotland Yard's eye. But it is only when the most recent of these crimes ends in murder that Inspector West begins to disentangle the clues.

The man who is killed is the watchman at Jefferson's, the largest department store in London. He had been living with his beautiful daughter, Rosie, and his son-in-law, Billy Mulcaster, both of whom West questions after the fact. Rosie's grief strikes him as genuine enough, but behind Billy's he sensed fear. Also there is an unexplained bruise on Billy's jaw, and the curious restaurant in which Billy works.

Gerald Sarkey, the elderly tycoon and chairman of Jefferson's, is far from helpful as West investigates. And West guesses that somewhere in Sarkey's tangled family there must be a clue. But no one is telling all, and in the meantime violence is erupting again. Inspector West is the only one who can help to uncover the secrets that have led so far to tragedy.