Dies the Fire

This is the first book in a spin-off series.

In the original trilogy, the island of Nantucket somehow gets caught up in a temporal storm and goes back in time to the bronze-age. Meanwhile, bronze-age Nantucket is sent forward to 1998.

This series started with the original trilogy (Dies the Fire, The Protector's War, and A Meeting at Corvallis). Basically, this book is about what happens in Oregon because of the temporal storm.