Dyer and Danforth from the Miskatonic University research team take their small plane through the unknown Antarctic mountain range--and land to explore the vast, cyclopean alien city that lies beyond it. Here at last they will discover the hideous secret of all life on Earth . . . but can they escape these uttermost vaults at the bottom of the world, and keep sanity enough to warn mankind...? The conclusion of At the Mountains of Madness!