Dunstan Leech, an unscrupulous gambler, victim of drugs, plans to marry his mother's ward, Kate Heathcote, that he may hide the embezzlement of funds entrusted to his care. His mother summons him from London to their country home, where he discovers Kate to be in love with Richard Blunt, who is tutoring his crippled half-brother Cecil. Unable to make Kate listen to his love, Leech plans to kill Cecil to gain possession of the money which will revert to him upon Cecil's death. He injects morphine into a prize bunch of grapes which is being saved for Cecil's birthday. The boy eats the grapes, dying from the effects. Leech's mother, Mrs. Jelf, determines to ruin Blunt in Kate's eyes by making it appear that a robbery has been committed and having the money discovered upon his person. The plot fails, and Blunt, whose suspicion had been aroused in connection with Cecil's death, leaves the house.