The hero and heroine of "Your Wife and Mine" are English aristocrats and are enjoying a protracted honeymoon in southern France. In England we see the man's cousin, who has thought himself the heir to title and estate, discovering that a child has been born to the young pair. He and his sister scheme to get rid of this impediment to their inheritance. They come on a visit to the honeymooners. The villainess sees the wife talking to her unknown acrobatic brother and persuades the husband that she is not true. The husband, in despair, goes on his yacht and orders the captain to put to sea. The villains have had a time-bomb put in the hold. The baby is stolen. The acrobatic brother hears of the bomb. Wireless warns the husband, and the yacht is brought back. The villainess is captured and forced to tell where the child is hidden. The husband has been stabbed and is in bed. The villain goes to destroy the child and finds the mother there alone. The acrobats are hurrying after him.