The plot concerns the mad scientist Boroff (Bela Lugosi) attempting to sell a superweapon to the highest bidder, opposed by Coast Guard Lieutenant Terry Kent (Ralph Byrd), for both personal and professional reasons.

It was made during the 2-year period when the Hayes Office put a moratorium on horror movies, Lugosi's usual genre, and in the midst of Byrd's notoriety for the highly popular Dick Tracy serials.

Hot on his heels are the Coast Guard, led by Lt. Kent, and the two reporters, with the expert aid of Jean's chemist brother, Dick.

Eventually Terry finds, and leads a squad against, Boroff's cave-based hideout, with disintegrator gas bombs exploding around them.

[1] The new scenes involved a substantial plot alteration to feature a made-up chemical, called arnatite, as a deadly explosive in and of itself, and other dialogue to cover continuity gaps arising from the editing.