Rebecca Larson is a busy woman. Between her nursing job and training for a Spartan Race, she doesn't have time for a social life. A weekend hiking trip with her girlfriend is strictly for the purpose of getting a high-altitude workout under her belt. Griffen Masters is not pleased his sister is bringing a friend on their annual siblings-only hike. And to make matters worse, the woman is human. She'll never be able to keep up. However, the moment she arrives, his world tilts—she is his mate. As if Griffen doesn't have enough problems wooing his mate and trying to keep his hands to himself for the weekend, a mysterious force causes him to need medical attention at the peak of the mountain. Miles Bartel is a long-time friend of Griffen and a vet. An added shock—Miles is also destined to mate with Rebecca. But the questions are piling up. What happened to Griffen in the first place? And how much light can Miles' grandmother, a medicine woman, shed on the situation? The mating is inevitable and urgent. Everything else will have to wait. But strange events occur nearly every day, keeping all three on their toes. And answers are not forthcoming. If something doesn't give soon, frayed nerves will start to affect their relationship.