Daring Deception by Barbara Freethy

He didn’t just break her heart, he broke her soul. He is the last person she wants to see again. And the only person who can help her solve a deadly case. When a bomb exploded at her college, Caitlyn Carlson’s life changed in an instant. Ten years later, she’s no longer a vulnerable, trusting girl, but a tough, ruthless, FBI agent. But her hard exterior covers a deep, aching hole in her heart.

Quinn Kelly has changed his life, too, trying to make up for the horrific mistakes of his youth. But some mistakes can’t be outrun or forgiven. Some feelings don’t stay buried, no matter how hard you try. An explosion at a local university takes them back to the past, to the one place they never wanted to go again…and to each other. They barely survived loving each other the first time around. The secrets and lies almost killed them. Will this be their second chance, or will this be the end of everything?