Dennis Nilsen was a Scottish-born serial killer who preyed upon young men and teenagers living on the margins of London life. He lured victims to his rented rooms with offers of food, alcohol, and companionship before strangling them in moments of calculated control. Nilsen kept the bodies for days or weeks, speaking to them and treating them as if they were still alive, revealing a disturbing need for companionship within his isolation. When decomposition forced disposal, he dismembered remains and burned or flushed them through his building’s drains. His crimes came to light only when neighbors complained of blocked pipes, leading police to a discovery that broke open one of Britain’s most chilling murder cases.