Sensing that the gifted children who performed so heroically in saving the world the previous year (The Mysterious Benedict Society, BCCB 5/07) would be getting lonely without one other, their leader Mr. Benedict arranges a transatlantic scavenger hunt for them as an anniversary treat. Alas, he and his assistant, Number Two, are kidnapped by his old nemesis and twin brother, Mr. Curtain, while they are setting the clues, and the happy adventure turns perilous for the children, who naturally escape the watchful eyes of their adult guardians and set off to rescue their beloved benefactor. Enough clues have been laid for them to follow kidnappers and kidnappees to a remote island where a possible botanical cure for Mr. Benedict's narcolepsy grows; unfortunately, that same cure has the power to plunge whole populations into deep sleep, making it attractive to the power-mad Mr. Curtain as well. Stewart knows his characters with the same deep intimacy as Rowling knows hers; the result is a remarkably self-assured mystery with the side benefits of developing character drama. His plotting is once again crafty and involving for readers as they figure out the clues alongside the children; the deliciously two-dimensional and sinister villains, as well as the helpers, both human and animal, lend a fairytale buoyancy to their quest. Every bit as chunky and satisfying as the first, this adventure will delight fans, particularly as young Constance comes into her own, discovering new talents along the way. Sudyka's black-and-white chapter headings add style and atmosphere.