Luck of the Devil by Denise Grover Swank

She quit drinking the day her mother died. Now she has to stay sober long enough to prove it wasn’t an accident.

Former detective Harper Adams is only days into sobriety when she realizes her mother’s car accident wasn’t an accident at all. The faded skid marks on the bridge. The drugs in her tox screen. The packed suitcase in the trunk, for a trip her homebody mother never mentioned. Something sinister happened—and Harper is determined to uncover the truth.
To do that, she accepts the assistance of the last man she should trust: James Malcolm, a crime boss with a shadowy past. He insists he’s only trying to help. Harper isn’t sure whether his offer is about justice or something else entirely, but she decides it’s safer to work with the devil you know. Malcolm gets results—and results are what she needs.

As Harper digs deeper, she unearths secrets powerful people want to keep buried. And the closer she gets to the truth, the more dangerous it becomes.

Staying sober is hard. Facing what really happened to her mother might destroy her.