Detective duo John Boarhog and Inspector Toadius McGee embark on a luxury airship to intercept an old adversary, but when the Society of Sleuths decides it is time for John's trial to gain full membership, there are no clear skies ahead.

After twelve-year-old John Boarhog's mom dies, the last thing he wants is to be schlepped off to the Jersey Home for Boys, where kids are forced to make skinny jeans for hipsters and are fed nothing but kale. Instead, he makes himself a snug home in the ceiling of the New York Museum of Natural History, where he reads anything he get his hands on and explores the artifacts afterhours. But when a rare Egyptian ruby--the highlight of the museum's new...