Rusty's Command (Team KOA Charlie #3)
Kendall Talbot

When nerdy cyber security specialist Sienna Blackwood seeks refuge on Hawaii's Big Island, her morning jog with her little dog turns into a desperate fight for survival when she stumbles on a murder cover-up near an ancient lava tube. Fleeing the scene, she bursts into the police station and crashes into a hauntingly familiar stranger who offers her help.
Ex-Delta Force operative Russell "Rusty" Callahan thought he'd seen it all. But protecting Sienna from a hail of bullets and vanishing evidence pushes his elite combat skills, and those of his highly-trained K9, Soda, to the limit. Deep in a labyrinth of underground lava tubes, they discover a secret door leading to horrors beyond their worst nightmares.
While paradise gleams above, a deadly underworld preys on the innocent below, forcing Sienna and Rusty into a desperate battle against ruthless gunmen—and the demons haunting their past.
Will they save the exploited victims? Or will their second chance at love end before it begins?