The Haymarket Strangler Returns! Boris Karloff plays a man who comes to believe that a serial killer from 20 years previously was innocent of the murders for which he was hanged. The case starts to consume him, literally... Based on the story "Stranglehold" written by Jan Read, pic unfolds as a creepy take of the Jekyll and Hyde kind. It's never overtly scary, but the atmospherics are palpable and the period flavours superb. This never resorts to cheap thrills, and unusually for the era of film making it doesn't rely on effects work for the transformation sequences - it is just Karloff acting! Plenty of horror movie staples are adhered to, such as a hanging, a coffin opening, an awful prison and an asylum, whilst that even though there's a little filler that could have been cut from the running time, Karloff and the intriguing mystery part of the narrative marry up to the atmosphere to round out a good old classic horror yarn. 7/10