Hearts Under Fire by Victoria Zak

With one of his own gone rogue and his heart under fire, the heat is on.
Overambitious Dragonkine, Stone MacMarcus, will risk his life to defend and protected his race. When top-secret information lands in the wrong hands and threatens the safety of the Dragonkine, his private security company is hired to neutralize the threat and retrieve the data. When one of his own goes rogue, the mission leads the danger straight to his mate. With time running out, Stone must complete the assignment before he loses his She-Dragon for good.
Done with Stone’s secrets and lies destroying their relationship, Crime Scene Investigator, Cynthia Sinclaire, begins anew, away from the heartache she left in Ember Brooke. Called to a crime scene involving a dead Dragonkine, she comes face-to-face with her past, Stone MacMarcus. Strange circumstances cause her to doubt Stone’s motives, but against her better judgment, the She-Dragon finds herself closer to him than ever before. Captured by his secrets and chained to her fears, does she have the strength to hold onto hope or will she send him away for good this time?