For Your Heart - Dark Covenant Retellings, #1

It has been seven years since Jeanette Sauderheim followed her best friend into Carver Hall Park...and came out alone. Jeanette has never gotten over his mysterious disappearance nor has she gone back into the park. While that traumatic night still haunts her, Jeanette distracts herself by balancing her time between trying to pass Spanish, hanging out with her friends, and reading the latest manga.
But, when a promise to a friend drives her back into the park, she's forced to re-live the memories of that night. Lost and confused, Jeanette crosses paths with Tamrin, whose violent reaction to her provides yet another reason to avoid the park. Tamrin, a knight of the Summer Court, has been sent to Earth to guard a garden of roses that hold special meaning to the queen of the Summer faeries. When his distraction at meeting Jeanette leads to her picking one of the Summer Queen's roses, Tamrin vows to right his failure to do his duty.
However, the equivalent of one of the queen's roses is a human heart and Tamrin's reluctance to readily exact the sum from Jeanette sets in motion a spiral of love, betrayal, and magic that could mean damnation for them both. This is a retelling of the Scottish Ballad of Tamlin set in the Dark Covenant Universe.