Flight 729 is bound for Chicago with a fortune in stolen jewels aboard.

Shannon infiltrates a ring of fur thieves.

Masquerading as a candy salesman, Shannon joins a murder investigation in upstate New York.

Strange poetry readings give Shannon a lead to a robbery gang.

Shannon befriends a narcotics addict hoping that she'll lead him to her supplier.

Shannon tries to nail a vice racket.

A gypsy con game brings Shannon closer to a mystic with ulterior motives.

A seemingly solid citizen, John Psaty, is suspected by assistant D.A. Bonacorsi of heading a complex numbers syndicate. Posing as the 
brother of a murdered gangster, Shannon manages to meet Psaty.

Shannon infiltrates a shoplifting racket by posing as a thief.

Shannon tries to straighten out crooked prize fights. 

Two youths kidnap a 7-year-old boy.

An extortion ring becomes Shannon's target as he zeroes in on their operation.

Shannon mingles with a trio of murder suspects, hoping to get one of them to turn state's evidence.

Shannon's after a thief and he has just one clue: the culprit is an Indian.

An explosion calls attention to a bootlegging operation in Manhattan, and Shannon sets out to find its operators.

Shannon's investigation of a racket takes him to Greenwich Village.

Shannon unwittingly jeopardizes a young boy's life.

Model Nancy Ward is Shannon's only link to a gang of jewel thieves.

Missing: a lawyer who represents the head of a bookmaking syndicate.

Shannon poses as a Bowery drifter to investigate the deaths of two derelicts. Louis Kemplar, a saloon keeper, was the beneficiary of the insurance policies that Kemplar had something to do with their deaths.

Shannon poses as an unemployed musician to get the dope on narcotics pushers.

The president of a produce firm is beaten and robbed by two thugs. The victim believes that the men are former employees of the firm. Shannon poses as an insurance investigator and attempts to find the criminals.

Assignment: smash a bogus union that preys on small businessmen. 

Wanted: hijackers who specialize in stealing electronic equipment.

Shannon, posing as an ex-con tries to break up a gun-rental racket.

Shannon meets the DA for the first time and accepts an assignment to track a gangland killer.