On Fire — Carla Neggers

In a tragic accident, Emile Labreque's research ship went down, killing a wealthy philanthropist and four crew members. Emile, his granddaughter, Riley St. Joe, and the captain, Sam Cassain, barely escaped with their lives. But when, a year later, Sam's body washes up on a beach, it looks as if someone is trying to cover up murder...and all evidence points to Emile.

Riley can't believe her grandfather is capable of the vicious crimes, and she is determined to clear his name. But when Emile disappears, Riley turns to the only person willing to help: John Straker, an FBI Special Agent, who is compelled to help Riley because of his friendship with the old man.

Riley and Straker are total opposites from different worlds, but they have something in common: a determination to expose a murderer and save Emile's life...and a passion they're finding harder and harder to ignore.