A fishing community on the Isle of Man. Pete, a fisherman, and Philip, a lawyer, have been friends since childhood. Pete, in love with Kate, the innkeeper's daughter, asks Philip to approach her father, Caesar, on his behalf, but Caesar angrily rejects his suit, insisting Pete is to poor to marry his daughter. Determined, Pete decides to sail to Africa to seek his fortune, and begs Kate to wait for him until he gets back. Reluctantly, Kate promises to wait.

Before he leaves, Pete asks Philip to look out for Kate while he is away. Despite the warnings of Philip's mother that a relationship below his class will hinder his intended career as a deemster (judge), Philip and Kate begin to fall in love, and when news arrives that Pete has been killed, the couple believe that their chance has come. Pete, however, is not dead, but has made his fortune, and is on his way home. Learning this, Philip tells Kate that she must keep her promise to Pete for his sake.

Pete and Kate are married, but Kate is distraught. When Philip returns to the Island after his appointment as deemster, she arranges to see him while Pete is out with the fleet, and confides in him that she is pregnant with his child. She wants to tell Pete, but Philip reminds her of the disgrace that this will bring upon her, and so she allows Pete to believe that the child is his. Eventually, however, the deceit is too much for Kate, and she deserts Pete and the baby and begs Philip to take her in. When Philip is more concerned about his impending court debut, she resolves to get back the child, but Pete refuses to give up the child, unwilling to accept she is not his.

Desolate, Kate throws herself off the dock, but is rescued and finds herself charged with attempted suicide, appearing in Philip's court. When Pete suggests that Kate can come back with him, she refuses, and finally Caesar reveals to Pete and the court that Philip was his betrayer. Philip confesses and resigns his post. Philip and Kate leave in disgrace with the baby