Desmond, chief of the police, admits that Detective Tait is the best man in his service, but says in response to his appeal for the hand of his daughter, "Nix on the son-in-law business." He tells him to go capture the green gang of counterfeiters and he may change his mind. The young detective stumbles on the rendezvous of the gang in a seemingly deserted building., but is discovered and overpowered, and is bound and gagged and left to the rats in the basement. A rat-catcher, who has been sent by the owners of the building to rid it of pests, finds the detective, but before he can get help is similarly conditioned by the counterfeiters. His pet ferret frees him by gnawing the ropes that bind him and eventually carries a note out through the tiny barred window to the street.