The Maya Bust: A Bone Guard Adventure. Bone Guard, #4

A secret stash, a hidden crypt, a father's love-spelled out in blood! When his commander's estranged daughter vanishes in Guatemala, Grant Casey treks a deadly jungle and dives a sacred cenote to free her from a drug smuggler looking for a stash in a Maya pyramid. Before his death in a rain of gunfire at her Quinceañeria, Raxha's druglord father encoded a map on a cacao cup, a map that might lead her to millions in drugs in the tomb of Maya royalty.
Unfortunately, his old mistress gave the cup to some Americans to prevent Raxha from completing the delivery and drawing the village back under the influence of the deadly Zetas cartel. Determined to claim her father's legacy, kidnapping is only the beginning of a quest that may end with Raxha tearing out the heart of her enemy. Awakened by a call from his old commander's ex, and sworn to secrecy about the rescue mission, Grant's integrity is torn.
Does he betray his client's trust, or the man who hated him for so long, the man who risked his life to save Grant's own? He sets up for his CO to follow the clues while he tracks down Lexi's friends to find the cup-and only then finds out Lexi's boyfriend is missing, too. How complicated could this get? Oh, yeah, Lexi is deaf, the police are complicit, and their adversary keeps a pet jaguar. When the ransom exchange goes south, Grant embeds with the bad guys in a desperate attempt to rescue the victims before they become the latest blood sacrifice. "A compelling adventure set in an exotic locale...a diverse cast of characters battles vicious foes while attempting to slay their own demons." ~ The Big Thrill