Harry Southard

In an English mining town during the 1870's, Joan Lowrie falls in love with Fergus Derrick, the new chief engineer who vows to improve working conditions. Joan's father Don, however, runs the mine and likes conditions just as they are. As a result, he quickly learns to detest the crusading Fergus, even to the point of trying to murder him.

Letters from the late mother of orphaned sisters Jane and Katherine seem to indicate that their father is Capt. Bob Dutton. Under orders from his superior, Colonel Harding, to acknowledge the children or quit the service, Dutton accepts responsibility for them. Shocked by his presumably checkered past, Cecile Harding, Dutton's fiancée and the colonel's daughter, breaks their engagement. One evening Jane surprises Capt. Robert Duncan, Dutton's rival for Cecile, stealing Bob's papers.

A young American man arrives in London to claim an estate he has inherited. One of the conditions is that he signs a paper stating he will never sell the estate. When he arrives at the estate he now owns, he runs into a ring of American gangsters there and discovers that the estate is the site of some buried pirate treasure.