The idea, widely believed by the world’s leading scientists and geographers, went like this: The weather wasn’t especially cold at the North Pole, at least not in summer. On the contrary, the dome of the world was covered in a shallow, warm, ice-free sea whose waters could be smoothly sailed, much as one might sail across the Caribbean or the Mediterranean. This tepid Arctic basin teemed with marine life—and was, quite possibly, home to a lost civilization.
