6x04 The Indelible Stain
First Aired: Jun. 06, 2012 on ITV1
Summary: A visiting professor is found strangled after delivering a controversial lecture. Lewis and Hathaway have no shortage of suspects, but when one of them is also murdered, her affair with a married professor of Criminology takes the investigation in another direction.
Main Characters in this Episode
DS James Hathaway: [Rhetorically] What's a clue but a mistake under another name.
DS James Hathaway: [referring to Adam] He's like the three wise monkeys rolled into one bloody-minded urban guerrilla.