Runaway Witness by Maggie K. Black

There is no safe place — not even in witness protection.

On the run after her witness protection location is exposed, Iris James trusts nobody — until the return of an undercover detective she thought was dead. Mack Gray was once Iris’s protector — and the man she was falling for — but he was forced to fake his death and go into hiding. Now with a killer’s henchmen on their trail, can he keep her alive long enough to testify?