Wealthy parliamentarian, Kenneth Stokes, discovers his illegitimacy when the woman he believes is his mother receives a blackmail demand from Molly Millar, the Stokes’ former cook, and commits suicide rather than tell him the truth. Vulnerable to ruin if the secret leaks, Kenneth seeks out Molly who threatens to expose him unless he buys her silence. When Molly tells Kenneth that Herbert Stokes is not his real father, a scuffle ensues, during which Molly is fatally injured.

Learning of Kenneth’s paternity Herbert rejects him, suffers a heart attack and loses his memory. Kenneth sends Herbert on a recuperative cruise hoping his memory will return at sea.

Molly’s ghost threatened revenge against the entire Stokes family and plagues Herbert, who believes he has lost his mind. Halfway across the Atlantic, Herbert sees death as his only escape from madness. But will he take it? And can he take Molly’s ghost with him?