Mountains Made of Glass by Scarlett St. clair

A deliciously hot and wicked retelling of classic Grimm, Hans Christian Anderson, and Irish fairy tales, first in a series of seven entwined fairy tales. When Gesela unwillingly kills a toad that lives at the bottom of the town well, she is kidnapped by five Elven princes, her punishment: banishment to their brother, The Beast.

Gesela expects to be the prisoner of a hideous monster, but the beast turns out to be exquisitely beautiful, and rather than lock her in a cell, he offers Gesela a deal. If she can guess his true name in seven days, she can go free. Gesela agrees, but there is a hidden catch—she must speak his name with love to free him, as well.

Can either of them learn to love in time?