Viewers of The Invisible Strangler (1976) must be willing to suspend disbelief, if only for a moment, and then the whole thing makes perfect sense. A wacko in a nuthouse glowers at his locked door. The insults of a fellow inmate trigger a flashback. The wacko fatally strangles his own mother, then returns to his cell and has mastered the trick of becoming invisible! Still with us? The fun is about to begin. The titular invisible strangler has a score of grudges that need to be settled. A manly do-gooder is on the killer’s trail, attempting to stop him before the next victim is claimed. Not being able to be seen has its tactical advantages!