Richard Bruce, an American in fog bound London stumbles into the midst of international intrigue, with Rose Thorne, an innocent dupe. Together they try to unravel the mystery, enlisting the aid of a cat burglar named Holmes, who they bump into along the way.

In this action-filled spectacle set in ancient Pompeii, a blacksmith becomes a Roman gladiator, though his rise to wealth and power is jeopardized by his son's Christianity and the eruption of Vesuvius.