Piano wire isn’t actually from a piano, of course. It’s a similar material made of a razor-thin carbon-steel alloy that won’t break for anything. The thing is wrapped around the victim’s neck posthumously and tightened like a garrote. It first cuts through the jugular vein, then the carotid artery, then the rest of the meat and the spine. In the end, the head just pops off. Human strength isn’t enough to do this, usually, but there are plenty of tools that make it possible. An industrial wire loop gauge usually does the trick. The most dangerous ones are electric. High-end cartel hit men call them autogarrotes. They’re about the size of a large cell phone and can be bought at any number of industrial supply stores. In civilian life they’re used for adjusting small suspension wires, or testing fishing lines. Once the thing is in place around somebody’s neck, though, it’ll chop off his head in less than a minute. Almost no skill is required. The wire loop leaves a clean, surgicallooking cut that’s straighter than anything you could manage outside a hospital.