Harlequin Intrigue Series by Janice Kay Johnson

Will he complete his missionbefore she blows his cover?When Leah Keaton arrives at her family’s remote mountain resort, a group of armed insurgents are waiting to capture her. After Leah’s failed escape attempt, Spencer Wyatt, the group’s second in command, takes her under his protection. Spencer is an FBI agent deep undercover, and Leah’s presence is disrupting all his best-laid plans. But to keep her safe, he’s willing to risk his mission—and his life.

Death doesn’t frighten him …but the thought of losing her does Former navy SEAL Alan Burke is on the trail of a serial killer—and determined to protect Jo Summerlin. As stubborn as she is beautiful, she insists on following a hunch into the limestone caverns snaking beneath Missouri. They both know that they may be descending into a monster’s lair. To get Jo out alive, will Alan have to make the ultimate sacrifice?  From Harlequin Intrigue: Seek thrills. Solve crimes. Justice served.