James P Hogan

"A valuable syntheic gem is stolen and the head of the Metropolitan Diamond Syndicate is the chief suspect. The scientist responsible for "creating" the precious stone is murdered and Captain Drummond swears vengeance. The trail leads to a house on the outskirts of London where he finds his fiance, Phyllis Clavering, and his loyal vatlet, Tenny, imprisoned by a notorious arch-criminal who will stop at nothing to learn the secret of the artificial...

A double feature of the adventures of dashing sleuth Bulldog Drummond. In Bulldog Drummond's revenge, Drummond seeks to retrieve a cargo of powerful explosives and track down the gang of ruthless spies who stole it. In Bulldog Drummond's peril, Drummond's wedding is interrupted by murder and he must find the missing formula for a synthetic diamond.