Marriage Under Fire: Grayce Walters Mystery Series 4 (Grayce Walters #4)
Jacki Delecki

Duty and discipline are Hunter Hines’s credo, guiding every decision and every action. But constant proximity with the fierce and enticing Maddy is veering his mission wildly off course. Although their role as man and wife is only pretend, there is nothing false about his out-of-control desire for his partner.
When Maddy’s life is threatened by an ISIS cell, protecting her becomes the only mission that matters, and Hunter is willing to break all the rules to save her. As the danger heats up around these two veteran heroes, Maddy and Hunter must walk a narrow path between passion and survival.