Using Gyro Gearloose's super solvent, Scrooge "digs" a tunnel straight to the Earth's core... and risks destroying the world in the sixth complete, chronological book of Duck adventures by Don Rosa! Stories in this latest volume also include "Hearts of the Yukon" (an untold tale of Scrooge, Glittering Goldie, and the Klondike Mounted Police), "The Lost Charts of Columbus" (featuring the evil Azure Blue), and the Beagle Boys face bug-size battlers in "The Incredible Shrinking Tightwad!"