What if history had taken a different path, made a detour, and deviated just a little bit from the road it chose? Here, Harry Turtledove explores such "what ifs" in twenty alternate-history stories ranging from ancient times to the far, far-different future.

Persia has conquered Greece; Athens is in ruins. Yet even under Persia's rule, the power of the people can never be completely broken...

A werewolf boy tears through Cologne's medieval streets in search of sanctuary from the angry mob. But who will shelter a creature so hated and feared?

A student from the far-off future sets off on a field trip to study Genghis Khan - and finds him in the twentieth century?

And many more!