Invincible

Description for INVINCIBLE by Joan Johnston:

Bella Benedict's five grown children are scattered around the world like a handful of precious jewels. Now she's dying and she has one last, secret wish. To bring her children home. And to give them what she once had: a marriage of passion.

Wealthy playboy Max Benedict has no interest in long-term commitment. He had his heart broken once and that was enough. Instead, he travels the world, working as a sometime spy for the CIA. When he's asked to investigate a foreign threat against the president, he doesn't think twice about accepting -- until he hears who he'll be working with in London.

FBI Special Agent Kristin Lassiter is under investigation and on the verge of losing everything -- her savings, her job, her beloved father. So when Bella Benedict approaches her with the offer to pay her mounting debts, she's tempted to accept. But there's a catch -- a big one. Bella wants Kristin to win the heart of her son Max, the very man who destroyed Kristin years ago. A man unaware he fathered her nine-year-old daughter. If Kristin succeeds, she'll get the money she needs -- and the priceless Blackthorne rubies Bella has offered to sweeten the deal. The only problem is, can she win Max's heart without falling back in love with him?

This is #1 in The Benedict Brothers Series.