For most of the years in the history of this country - except for Las Vegas and Atlantic City - gambling has been outlawed. Even today, one cannot just set a gambling hall without a license and all sorts of other red tape. However, back in the M Squad days (and before), gangsters used to rent out a big room for a night, set up show with some craps tables and the like, and then move the next day. Word had gotten out among some big gamblers, so they also found suckers.....er, customers.
The dice were rigged many times.and that's what leads us to this particular story. A well-heeled Chicago businessman looking for some action, gets swindled at one of these places and doesn't like it. He knows the dice were loaded and winds up getting booted out of the joint when he protests. He's lucky he didn't get roughed up.
Anyway, he goes to the cops the next day, points out the building to "Det. Frank Ballinger," and Frank and his squad go to work trying to arrest the guy who's handling the gambling operations in the city. They know who it is; they just have not ever been able to get proof. Maybe now, they can get somewhere.
One big tip leads them to a woman on Rush Street, a lady named "Margo," who directs rich guys to these games. Margo is played by Rose Marie, whom older folks know well from "The Dick Van Dyke Show" as well as games shows, etc. Rose Marie was popular woman. She's interesting in this episode, too, with some snappy remarks as she did on those other shows.
Also in this episode, for film noir buffs, is Paul Maxey, a name you may not know but a figure you'll recognize! He was the famous "fat man" on the train in "The Narrow Margin" (1952, then re-made in 1990).
All in all, this was a good story and very unpredictable, with a lot of good actors who played tough guys. One really didn't know where this story was headed, thanks to some interesting characters inserted in the story fairly early on.