Return to the Hollow Earth is Rucker's second steampunk novel featuring Mason Reynolds. In 1850, Mason and his wife Seela embark upon a perilous trip around Cape Horn to San Francisco. Their ship sinks, but they're saved by a tentacled, flying nautilus--who carries them to meet Edgar Allan Poe. Poe leads them on a return voyage to the Hollow Earth, passing through the throat of a thousand-mile-deep maelstrom at the North Pole. Within the Hollow...