Newbie linguistics professor Mackenzie Campbell longs for love and success but works all the time, can't connect with her students, and is afraid she's a second-rate teacher. In the midst of finals, she receives a phone call from her ex-boyfriend, Charlie, begging her to join him in the remote Lake Powell canyons. He wants her to authenticate an ancient Aztec codex. Discovering a genuine codex would stun the linguistics world--but it's too risky for Mac, on so many levels.

When Mac discovers that Charlie has disappeared, she impulsively manipulates her way onto an archaeological expedition to find him. There, she meets Sullivan, the expedition's brash, insensitive guide who thinks she needs baby sitting. His goading incenses her, but as they battle their way through unrelenting canyons, she's forced to acknowledge her growing respect for him.

After a kiss in a cavern, they have a night of steamy sex. But is their relationship just the result of two people bonding during life-threatening events? And what about Charlie?

It takes all of Mac's linguistics chops to decipher obscure clues, outwit devious expedition mates, and battle hazards that would unhinge even the bravest linguist. In the end, she realizes her most difficult task will be deciding between a known love and a new one. If she makes it out alive, that is.