The Pinkerton Agency, also known as The Pinks and The Eye That Never Sleeps, was an infamous spy organisation that flourished as far back as the 19th century. (PROSE: Shakedown) After meeting the Sixth Doctor and Evelyn Smythe in Ford's Theatre on 14 April 1865, Henry Clay Ford became convinced that they were Pinkerton agents. (AUDIO: Assassin in the Limelight)