
Ben's in danger of spending his holidays cooped up in a caravan with his Mad Aunt Gwen. But by luck (and bribery), he gets a place on the school trip to an outward-bound centre in Wales, along with Barney, Jenks and, of course, Agent Z. Abseiling, orienteering, sinking enemy canoes and sabotaging toothpaste are all in a day's work for the Crane Grove Crew. But then they uncover a news clipping which reveals that their centre manager, the affectionately nicknamed 'Grenade-head', is in fact an escaped bank robber. He's planning to recover the buried loot any night now and Agent Z and the crew intend to be there when he does. If you think that sounds like a downright ridiculous plan, you'd be right. Especially as the escaped criminal story turns out to be the inventionof the crew's new pal, Roz and for once, the jokes on them! Mark Haddon has a sharp understanding of what makes children tick, and they will delight in the ever more daring, ever more hilarious missions of Agent Z and his three creators.

by Paul Geraghty
This captures that same anarchic energy where kids orchestrate increasingly elaborate pranks with military precision, except here the two protagonists are rival pranksters who team up. Barnett and John write with the same sharp comedic timing Haddon uses—the humor lands because the characters take their ridiculous schemes completely seriously, and the adult world keeps missing what's right in front of them.
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by Susan Hill
A mystery wrapped in adventure where a group of kids must figure out who this strange boy really is while dealing with increasingly bizarre threats. Like Agent Z's crew, there's genuine camaraderie between the characters and real stakes underneath the humor, but Winick adds a sci-fi twist that keeps you guessing about what's actually happening—the reader is solving the puzzle alongside the kids.
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by Barbara Taylor
Here's your surprise pick: it's historical fiction (set in Victorian London with young Ada Lovelace and Mary Shelley), but it reads like a caper novel where two brilliant girls solve crimes while navigating a world that constantly underestimates them. The humor is drier and more clever than Agent Z, and there's real historical detail woven in, but that same sense of underdogs outsmarting everyone around them runs through it.
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by Mari Lu Robbins
Published in 1967, this proves that the formula of kids on an adventure solving a mystery while learning about themselves is timeless. Two runaways hide in the Metropolitan Museum of Art and get caught up in an art heist mystery. Konigsburg has Haddon's gift for making you care about the characters while they're doing something completely mad, and the pacing builds the same way—small mysteries leading to bigger revelations.
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by Chris Lambrianou
A group of kids gets locked in a high-tech library overnight and must solve puzzles to escape. It has that same collaborative problem-solving energy as Agent Z's missions, where each character brings different skills to the table, and Grabenstein peppers it with genuine humor about books and libraries without ever being preachy. The setting is unusual enough that it feels fresh, but the core appeal—kids working together against the odds—is exactly what makes Haddon's book work.
View bookBorn 1962
Mark Haddon (born 26 September 1962) is an English novelist, best known for *The Curious Incident of the Dog in the Night-Tim*e (2003). He won the Whitbread Award, the Dolly Gray Children's Literature Award, the Guardian Prize, and a Commonwealth Writers' Prize for his work.
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