Under-rated giallo with a linear and coherent plot, rare enough in this genre, thanks to the Edgar Wallace source material. Not quite up to Solange (also based on a Wallace novel) in terms of style or impact but better than Lenzi's Eyeball and Spasmo. Weak points: bland leading man and typically unmemorable Ortolani score. Aside from a drill scene, the violence is restrained. Good dubbing and fair enough English dialogue translation in the Greek video I saw. Recommended as a second-tier giallo.