The world that Denny inhabited was a world before modernity in any meaningful sense.

The ice ages were ongoing.

The global climate was dramatically different from today — cooler and drier across much of the Northern Hemisphere, with ice sheets extending from the poles and depressing sea levels significantly below modern levels.

The landscape of the Altai Mountains was a mix of steppe, forest-steppe, and highland environments, rich in large animals: woolly mammoths, woolly rhinoceroses, cave bears, cave lions, horses, bison.

In this world, the Neanderthals occupied a range that extended across Europe, the Middle East, and western Asia.