The Deadly Betrayal

With war waging Jacob must leave his wife and daughter behind as he and his men ready the defenses of England,it pained him to leave them but orders are orders. Everything is going to plan until a Carpal and dear friend gives him the tragic news.Death.Death had hit the city,Death has taken them from him.
But orders were still orders,they moved out Jacob having the calm of killing his enemies settle around him like a blanket - set out with his men to do what needs to be done.
But they have been compromised,sold out to the enemy.
Who would dear betray the crown?