A wormhole through time opens up between the near-end of a famous battle, and the losing nations current-day home. A hundred thousand or so soldier walk away from the certain death and into a great mystery of history, into the modern times to see what became of their homeland. What do they do? How do they react?
Example: Stalingrad , Jan 1943. The German forces are surrounded and know they are totally screwed, freezing, exhausted, and nearly out of food and ammo. A wondrous portal open up, and someone walks through and offers them a portal back to Germany, but 78 years into the future. Most of them take it, and walk out, guns in hand and what ammo they have remaining, and disappear like a wraith in the night. They appear in a modern Germany, full of socialists (which they are OK with, generally), a lot of people who hate Nazi (somewhat more of a problem), and millions of dark-skinned immigrants and sacrosanct Jews (Ummmmm, Huston, we have a problem…). Pretty sure that hilarity does not ensue, but what, exactly would?
Not a book I could write and do justice, but sure would like to read. Kratman or Ringo would be a better choice.