Redemption (The Boris Chronicles, #4)

Eighty years.

It has taken Boris that long after the fall of world civilization to finally create a stable realm. Yet now that kingdom faces threats on multiple fronts. 

A hostile force gathers to the west, seeking to rebuild Russia with cruelty and oppression.

To the south, a force with a mysterious weapon is threatening his borders.
Forced to split his forces, Boris has to place his untested heir in command of one group. No one else but Olaf can be safely sent, although it tears Boris apart.
Will Boris succeed at keeping the wolf from the door and keeping his legacy alive? 

Will his eldest son survive and triumph, or perish in battle?