Chasing A Shadow. Bayou Bounty Hunters, #5

Addie Hawk, a recovering alcoholic, has spent five years atoning for a bad choice that cost her custody of her son. The boy is now seven and lives with his father and stepmother, a woman Addie despises. Now, however, Addie believes her former husband and his wife have stepped over the line by allowing an ex-convict to move in with them upon his release from prison, thus endangering the little boy Addie loves more than anything in the world. Quinn Connelly just got out of jail after serving a quarter of his sentence for simple assault for punching the man who stole his girlfriend.
Properly chastised, he's determined to deal with his anger. He's just landed a job as a licensed fugitive retrieval agent and private investigator. Bringing bail jumpers to justice helps ease the aching loneliness in his soul. He relishes every minute he spends helping others and making the world a safer place. Quinn doesn't count on is being sucked into Addie's desperate fight to win back custody of her son.
She asks him to pin a crime, any crime, on the ex-con her former husband and his new wife have taken in, but he refuses. Then the boy claims the man assaulted him, and the ex-con disappears. Not willing to wait for the cops to find him, Addie begs Quinn for help and the two of them set out on an intrastate trek that may cost them their lives.