These missions are about Mike's life.
Mike is good man. he lost his family when he was in the army.
now he's living bad days. no money, nothing to do. he just has a house, a car and a boat. he lives in a small town in the desert. someone named "Carl Parker" planing to buy this small town for a project he's working on it.
But Mike Joins a strong Organization. and meet a new friend, Johnson.
... play the missions to know all the story about Mike.

Good luck!