The disappearance of Sophie de Greer, a "superforecaster" who predicts voter reactions to British government policies, drives Herron's terrific eighth Slough House novel (after 2021's Slow Horses). Since de Greer might be a Russian plant, two important people want her found: Anthony Sparrow, the prime minister's slimy enforcer, because he hired de Greer and wants to spare the government humiliation, and Diane Taverner, MI5's ruthless chief, because she knows Sparrow will blame her if de Greer turns out to be a spy. The actual work of finding de Greer falls to the so-called slow horses of Slough House, "the fleapit to which Regent's Park consigns failures, and where would-be stars of the British security service are living out the aftermath of their professional errors." Every piece counts in the intricate jigsaw puzzle of a plot, but the book's main strength is its dry, acerbic wit (Sparrow is "a homegrown Napoleon: nasty, British and short"). The result is an outstanding mix of arch humor, superb characterizations, and trenchant political observations. The forthcoming Apple TV adaptation of the series is sure to win Herron new fans. Agent: Juliet Burton, Juliet Burton Literary (U.K.). (May)

Herron's Slough House series, starring a group of MI5 rejects written off to the deep minors of British espionage, has long been a critics' favorite, but this eighth installment, buoyed by a new TV series, may be the one to launch it to the genre stratosphere. The "slow horses" of Slough House are mired in busywork as usual ("You could spend all day shoveling sand, but if you were standing on a beach, the results weren't noticeable"), but their foul-mouthed, ill-kempt leader, Jackson Lamb, both the biggest reject of all and an eccentric genius, has a plan to get some of his own back while bedeviling one of his many antagonists, MI5 chief Diana Taverner. "Superforecaster" Sophie de Greer, the prodigy of the PM's chief advisor, has disappeared amid rumors that she may be a Russian spy. Can Lamb turn the slow horses loose to find de Greer, simultaneously embarrassing Taverner and bringing down the power-hungry chief advisor? Lamb on the rampage is a joy to behold ("Get the bit between my teeth," he explains, "I'm like a dog with a boner."), and Taverner's enlarged role here is an additional delight, as she fights against becoming a high-level slow horse herself. If le Carré brought moral ambiguity to the spy novel in place of Bondian glamour, Herron one-ups the master by showing us that ambiguity has its uncouth comedic side. HIGH-DEMAND BACKSTORY: The recently launched Apple TV series Slow Horses, starring Gary Oldman as Jackson Lamb, will bring Herron an avalanche of new readers.

The screw-ups, has-beens, and never-weres who've been shunted off to Slough House are upstaged by incompetent spies at far higher pay grades in this eighth series installment. Swiss native Dr. Sophie de Greer, whom hard-charging bureaucrat Anthony Sparrow brought to the U.K. to work on Rethink#1, his think tank, may be a superforecaster at predicting trends, but one development she doesn't seem to have anticipated is her own sudden disappearance. When ex--MI5 chief Oliver Nash, acting at Sparrow's behest, asks his former colleague Claude Whelan to shake a few trees and see if she falls out, Whelan can see nothing but downsides--especially if, he frets, "someone triggered the Waterproof protocol" Whelan himself set up. If de Greer did come to grief, after all, the most obvious suspect is none other than Diana Taverner, who holds down the First Desk at MI5. Diana, for her part, is busy trying to figure out the agenda of her smirking Russian counterpart, Vassily Rasnokov, who's popped up in London from behind a false identity that wouldn't have fooled a child but fooled the spooks who were supposed to be following him. Although Diana takes time out for a meeting with her regular sparring partner, Slough House zookeeper Jackson Lamb, the problems here go far beyond Lamb's slow horses, as she realizes when someone does trigger the Candlestub protocol, transforming her instantly from the head of MI5 into a woman on the run. Once again, Herron summons a witches' brew of double talk, petty rivalries, and professional paranoia, this time less John le Carré than George V. Higgins, to demonstrate that any talk of the intelligence community outside Slough House is nothing but an oxymoron. More proof that the enemies of the state are no more than a pretext for infighting to the death among the agencies. Copyright (c) Kirkus Reviews, used with permission.