S5·E15 Cat's Paw

Larry Collier, newspaper editor and Barney's brother, is killed while trying to establish a link between corrupt police chief Abbott and Corley, the head of a ghetto mob who masks his illegal activities with an insurance front company. Barney, set up with a past as a crooked accountant, gets close to Corley by rescuing his secretary Millie - Corley hires him on when he finds out about his "past." Barney plants money to make it look like Corley's assistant Goslin is working against him, while the IMF use a phony seance to convince Goslin to quit with some incriminating evidence. Jim arrests Goslin with the evidence, a codebook, and uses it to force Abbott to back him as a mob boss then bribes Corley's guard to try and kill the mob leader. Barney rescues him and Corley runs into Jim, who threatens to take him to Abbott - knowing Abbott will have him killed, Corley turns state's evidence.