Unscrupulous gambler and drug addict Dunstan Leech has embezzled money entrusted to him. Hoping to cover the theft he plans to wed his mother’s ward Kate Heathcote, who is tutor to his disabled brother Cecil, only to discover she loves Richard Blunt. Unhinged, due to his drug use, he poisons his brother’s food to clear the way to an inheritance while his equally dishonest mother Mrs. Jelf attempts to frame Blunt for theft. That plan fails and Kate & Richard marry departing for the diamond mines of South Africa. Obsessed, Leech follows and kidnaps Kate and the couple’s child fleeing back to England pursued by Richard. Held hostage at Leech’s estate, his dying mother gives Kate the evidence to prove Dunstan’s culpability in Cecil’s slaying but driven mad with guilt and haunted by Cecil’s spirit he commits suicide, and the young family are reunited.