Queen of Golden Age Crime, Margery Allingham, writes as Maxwell March. 

Inspector David Blest has two choices, jump or die.

Trapped aboard a motor boat with a pistol to his head and the life of his unconscious companion on the line, he’d better make his decision quick.

On the trail of the mysterious death of a gentleman in the Senior Buffs Club, young Inspector Blest is led to a fashionable seaside resort on the English coast, where the locals appear all too happy to help his investigation. Things take a turn when Blest meets Judy Wellington, an apparently sickly young woman desperate to escape her past. But who is Judy Wellington? What exactly is she running from? And how has Blest found himself the murderer’s next target?