The Hunted Wife. The Sullivan Protectors, #1

A marriage between strangers was supposed to solve both their problems. Instead, it may put them both in the path of a killer. Billionaire Adam Sullivan has built a global technology company, but the sprawling Colorado ranch he shares with his six brothers still doesn't feel like a home. He wants a wife, children, and someone with whom to build a future. When he meets beautiful Millie Watson in a grocery store, one impulsive question leads them to the courthouse-and into a marriage neither of them expected.
For Millie, becoming Adam's wife offers more than a new beginning. It gives her a new name, a secluded home, and the protection she desperately needs. But Adam doesn't know that Millie is hiding from a powerful family or that a dangerous man is searching for her. As their practical arrangement becomes a real marriage, Millie finds the love and family she never believed she could have. Yet every tender moment is shadowed by the fear that her secrets will destroy Adam's trust-or bring violence to his door.
Someone is watching the ranch. Security has been breached, and the threat is moving closer. When Millie's past finally finds her, Adam will risk everything to save the woman he loves. But protecting his wife may require him to survive the truth she has been too frightened to reveal.