The Fighting Lover (1921)

Andrew Forsdale bets $10,000 that his friend, Ned Randolph, will fall in love with one of three young women within 30 days. Vic Ragner, a mutual friend, is to be stakeholder and judge. The candidates, Helen Leigh, Anna Hughes, and Julia Gunther, are obtained through advertising, and Andrew unexpectedly falls for Helen. During a weekend visit to the home of Andrew's aunt, the three women are suspected of being in league with thieves who have stolen a valuable diamond and killed Vic. Julia is revealed to be the confederate, Helen and Andrew are united, and Ned wins Anna but loses the bet.