Rejection came softer these days. Dickie heard occasional whispers on the Soho songlines, and these days even the useless were given a chance. The Service, like everyone else, was hamstrung by rules and regulations: sack the useless, and they took you to tribunal for discriminating against useless people. So the Service bunged the useless into some godforsaken annex and threw paperwork at them, an administrative harassment intended to make them hand in their cards. They called them the slow horses. The screw-ups. The losers. They called them the slow horses and they belonged to Jackson Lamb, whom Dickie had encountered, back in the Spooks’ Zoo.
— Slow Horses (Mick Herron), Loc. 5895–9