Pulpy, wildly overwrought, but entertaining co-feature from Columbia has a pre-"Ben Casey" Vince Edwards starring as a convict who breaks out of San Quentin with a container he thinks is "a pound of 100% snow", but instead of heroin it's actually radioactive Cobalt 60 and any exposure could decimate Los Angeles. Not a compact thriller (even at 75 minutes!), this suspense film is full of behind-the-wheel montages and bits of generic police business. Edwards smolders like a reckless mad-dog stud, yet when he's required to disguise himself as a businessman with glasses, he's adept and convincing at this transition. The other actors in the cast aren't as versatile, and the mechanical writing and directing certainly doesn't liven them up (they're all stock figures, though Vince's girlfriend does get in a few funny wisecracks down at the police station). Photographed by Lucien Ballard, the movie has a great, gritty look full of L.A.'s neighborhoods and back streets, and the tension does manage to build successfully even though just about everything in the picture is second-rate. **1/2 from ****