Robert Matthews (Emrys Jones) is arrested in Cornwall when he is mistaken for convict John Barlow, to whom he bears a striking resemblance. When Barlow hears of this, he makes his way to Matthews' cottage and takes his place. When there is a local shipwreck, one of the survivors is Anne Farrington, Matthews' fiancée. Barlow takes her in, maintaining his imposture, but soon discovers that Matthews is not all he seems.