Jerry Paris gave his best performance of the series as Martin Flaherty in this episode. It's a shame Paris left the series in mid-season. I know most purists will disagree with me here but I thought Paris was the best of the three sidekicks to Robert Stack's Eliot Ness in the series. Jovial and easy going Martin Flaherty provided a nice counterbalance to the grim and somber Eliot Ness. We didn't always get this counterbalance from Flaherty's successors, Cam Allison and Lee Hobson.
The episode itself is pretty good with nice performances from Jay C. Flippen and Darryl Hickman as the father/son numbers bankers who discover where they really stand in the underworld hierarchy when one of their collectors is murdered for refusing to pay off. The final scene is also a classic.