In Loving Resilience. Cryptid Keeper Series, #1

The Kelpie has killed before. It does not trust humans, and it has never once been curious about one. Until Harper Evans. She arrives in Scotland carrying damage she doesn't name and scars she can't hide; the kind left by a man who mistook possession for love. Harper has already survived her monster. She rebuilt herself from the wreckage, buried her old name somewhere on the other side of the world, and swore she would never be found.
She is not interested in handing herself to something dangerous again. Especially not something that watches her the way Luke Campbell does - too still, too focused, like a predator deciding whether to be patient. The Kelpie decides to be patient. For the first time in its long and violent existence, it does not want to drown her. It wants to keep her. And what it decides to keep, it will not suffer another to touch.
But Harper's past has always been better at finding her than she has been at running. Something is closing in; quiet, methodical, and certain...and she doesn't know it yet. Neither does Luke. But the Kelpie is already restless. If he finds her in time, there will be a reckoning. And if he doesn't, the darkness inside him will make sure there is one anyway.