The year is 1934 and Sir Wilbur Tennington has been living in India for several years, studying a sacred text with a holy man. From this he comes to realise that the constellations described therein can only be seen from the Arctic, and he develops the conviction that the civilisation that invaded what was to become Europe still exists, north of Ellesmere Island in the Arctic Ocean. Sir Wilbur calls together the same group that accompanied him in his previous search for a lost Inca city and they fly from San Francisco to Point Barrow, the second northernmost point on the continent. From there they press northward, next by dogsled, across an Arctic desert of frigid sand and the Agassiz Ice Cap. To their consternation, they find they are not alone in the land where the Midnight Sun never sets ..