When Sir Philip Harclay returns to England after a long absence, he finds that his childhood friend, Arthur, Lord Lovel, is no longer alive, and that the castle and estates of the Lovel family have twice changed hands. But a mysteriously abandoned set of rooms in the castle of Lovel promises to disclose the secrets of the past. After a series of frantic episodes and surprising revelations, culminating in a trial by combat, the crimes of the usurper and the legitimacy of the true heir are finally discovered.