On Deadly Ground — Susan Vaughan

****Part of a series, but a stand-alone novel with its own conclusion. No cliff-hangers.
DEVLIN SECURITY FORCE, Protecting Priceless Treasures
A desperate sister…Museum director Kate Fontaine made two promises to her dying father -- protect her ne'er-do-well brother and return a stolen statuette of the Maya god of earthquakes to its temple. But when her brother is kidnapped and the price to save him is the priceless artifact, keeping one promise means breaking the other. In a no-win situation and facing a dangerous trek through the jungle, Kate is forced to rely on a guide she doesn't trust… yet whose touch makes her yearn for so much more.
A cynical guide…The only person Max Rivera can truly count on is himself. That's why he prefers to work alone. Unfortunately his Devlin Security Force assignment to guide and protect Kate includes covertly finding proof her kidnapped brother has sold black-market antiquities. And sticking close to this delectable and vulnerable woman proves more dangerous to Max than all the threats in the jungle.
A race against time.While following the kidnapper's instructions, Max and Kate must outrun black-market smugglers and a predicted earthquake in a race that takes them from Washington to England and into the Costa Verde jungle. But as perilous as their quest becomes, when desire flares between them, risking their lives seems simple next to risking their hearts.