Here’s a cold-blooded little caper for ya. Clocking in at a lean 62 minutes, Inner Sanctum is “based” on the mystery radio series of the same name that ran from 1941 to 1952. I’m not sure based is the right word – it’s more like they just took the banner name and used it to market the film. Either way, Inner Sanctum is a great murder story framed around an intriguing train ride that bookends the main narrative. It’s definitely a B-grade noir, with very low production values. But what it lacks in pizazz it makes up for in cynicism and brute force.