Both B and E lost their mothers at young age, their fathers have a past as friends/colleagues, shit happens Bella gets targeted and Charlie contacts the Cullen's. I don't want to give away too much, but it is a good read.
It's somewhat graphic in the violence department, but it is so well written that you don't feel the that was unnecessary feeling. The way Edward is with Bella in the later chapters is natural and unhurried.
Go read it, I know you'll love it. ;)
The definition of a mercenary is a soldier for hire. Secret identities, smart and strong women, a fight to keep loved ones safe, and maybe love and friendship along the way. Canon couples. AH/AU/ Rated M for lots of reasons, including violence and lemons.