Zeuglodon — James P. Blaylock

A skeletal hand clutching an iron key lies hidden within a mermaid's wooden sarcophagus; a hand-drawn map is stolen from beneath the floorboards an old museum; an eccentric sleeping inventor dreams of a passage to the center of the hollow earth, and by dreaming of the passage, brings it into being....

Pursued by kidnappers thinking of riches and murder, Katherine Perkins and her two cousins, junior members of The Guild of St. George, must descend into the depths of the hollow earth in order to return the Sleeper to his ancestral home on the shores of Lake Windermere. But to awaken him might mean the end of his dream, the closing of the Windermere Passage, and the three intrepid explorers marooned in a savage land forgotten by time itself....

Zeuglodon, set in the world envisioned in James Blaylock's The Digging Leviathan, is a landscape of color, mystery, and adventure, in which reality and fantasy are shifting currents, and nothing is quite what it seems to be.