Four Favorites #17 (1945)

In the remote mountains, Lash Lightning and his partner Isobel investigate a series of mysterious deaths among young bicyclists, all found in the roaring streams—just as thunder rumbles ominously nearby. Their search leads them to the secluded estate of the reclusive Professor Bixby, whose seemingly hospitable demeanor hides a dark secret tied to ancient rituals and a hidden cave beneath the house. As the storm builds and strange forces take hold, the duo must fight to survive a deadly trap before the next sacrifice is claimed.

In "Unholy Death," Captain Courageous races to rescue the kidnapped daughter of a wealthy manufacturer, following a trail that leads straight to the sinister Swami—whose dark ambitions target the secret blueprints for precision instruments vital to the Superfortresses, crafted at the girl’s father’s plant.