Pay him a little bit, he's a little bit tough. Pay very much, he's very much tough. Pay too much, he's too much tough.

1940s Hollywood private eye Toby Peters returns—unfortunately, with an awful case of the flu. Peters is coughing and sniffling his way through the Chicago underworld in a desperate attempt to clear the name of Chico Marx, who is accused of owing $120,000 in gambling debts to the mob.

In addition to gangsters, Peters has to deal with Chico's partners. One of them doesn't speak—he's a silent partner—and the other one goes around with a black mustache. Though if he had his choice, he'd go around with a little blonde.

Things may be looking rough, but with the help of a few other tough guys who're siding with him—Al Capone, Richard Daley, and Ian Fleming—Peters just may have a chance.