Crash

Tessa Kincaid ends up in the ER after a frightening medical emergency, and the doctor who takes her case is Blake Morrison — her brother's best friend, and the man who broke her heart. As her unexplained symptoms escalate, Blake becomes obsessed with figuring out what's really happening to her, certain someone is deliberately hurting her.

Their old, forbidden attraction reignites under the pressure, and Blake grows increasingly protective and possessive as the mystery deepens. Forced proximity, a friends-to-lovers history, and a brother's-best-friend taboo drive the romance alongside the medical suspense plot.

Crash is Book 1 in Kathy Lockheart's Sinners and Saints series — each entry follows a different couple and stands alone with its own happy ending, though later books revisit the same circle of characters.