In this fourth installment in the award-winning Chronicles of the Monster Detective Agency series, fledgling Monster Detective Will Allen is confronted by daunting new horrors. He may have triumphed over giant scorpions, flying sharks, and schoolyard bullies alike (and even survived his mother's cooking), but now he faces a challenge that all of his skill, cleverness and bravery are powerless against - dealing with GIRLS!

And even if he muddles his way through that nightmare, can Will still rise to the occasion and save himself and his friends from living manifestations of their worst fears when he has been abandoned by his monster detective mentor, Bigelow Hawkins, the Great Monster Detective, and his magical detection tools, the RevealeR and the MonsterScope, suddenly lose their monster-fighting powers?