Katie, Lily, and Jasper attach their flying Gyroscopic Sky Suite to the Moose Tongue Lodge and Resort, where they mingle with other child heroes found in books, and where they become embroiled in a mystery involving lederhosen-clothed quintuplets and a screaming ventriloquist.

In the mid-1950s, Yggdrasil Birnbaum and her friends, Seamus and Neddie, journey to Old New Hackensack, which is on another plane, to try to learn why ghosts are disappearing from the Birnbaum's hotel and other Hollywood, California, locations.