Having endangered his life by foolishly gambling away funds entrusted to him by the Carbonari, an Italian secret society, London banker Bernard Huddlestone appeals to Northmour, an adventurer, for protection. Northmour takes Huddlestone and his daughter Clara to his castle in Scotland, offering them safety in return for Clara's hand in marriage. There Clara encounters Frank Cassilis, an old adversary of Northmour's, and falls in love. Trouble brews between the two men, but when the Carbonari discovers Huddlestone's hiding place and storms the castle, the fugitives band together to fight the avengers. Coming to the realization that only his sacrifice will appease the attackers, Huddlestone steps out and meets his death. Northmour, deciding that married life would prove too monotonous, gives up his claim on Clara to Cassilis.