Down to the Wire by Patricia Sargeant

Reunited by danger…

…and racing against the clock

On the trail of a hacker, IT security expert Malachi Touré finds…a woman from his past he’s never gotten over. Dr. Grace Blackwell is no hacker. She’s a medical researcher, and someone has stolen a potentially deadly formula from her computer. Despite the still-simmering attraction between them, Mal is wary of trusting her again. Then everything changes when a killer has Grace in their sights…

From Harlequin Romantic Suspense: Danger. Passion. Drama.