After the Downfall

From Turtledove

After the Downfall, Night Shade Books, is a fantasy novel by Harry Turtledove.

In April 1945 Soviet forces are storming Berlin. Captain Hasso Pemsel and the survivors of his company are under siege in Berlin's Old Museum with orders to fight to the last man. Pemsel notices a large stone artifact that had not been removed to a safer location and is curious about it. In a lull in fighting, he crawls over and reads that it is the Omphalos from Zeus' temple in Delphi, a keystone and bridge between worlds. On a fatalistic whim he sits on it and is immediately transported to another world where magic works and wizards ride unicorns.