Serial killer Ed Gein shocked the US to its core in the mid 1950s as the dismembered corpses of 15 women were found in his isolated Wisconsin farmhouse. Worse still, he'd made trinkets and trophies out of the dead women's bodies. Alfred Hitchcock's Psycho, The Texas Chain Saw Massacre, and The Silence of the Lambs and, of course Ed Gein, which follows on Channel 4, were inspired by Gein's ghoulish crimes. The Real Silence of the Lambs asks what could have driven a mild-mannered farm boy to such levels of depravity?