Within the Darkening Woods - Twisted Worlds, #1

It's been five years since the world was forever changed. Overnight, parts of the mortal world disappeared and were replaced by fragments from another realm, taking entire counties and countries and leaving the lands of fae, sirens, and other creatures out of legend in their place. People no longer have to imagine what it would be like to live in a fantasy world, because now they live in one. Amber, though, likes to pretend that these strange new neighbors don't exist.
And since the elven forest that replaced Saint Cloud, Minnesota is completely isolated from the surrounding world, that's been relatively easy. She just wants to find a job with her degree in landscape design that will fulfill her enough to ignore how the rest of her life-especially her love life-is in a million pieces. But when Amber is poisoned by a giant spider that escaped the forest, she has no choice but to acknowledge that she lives right beside magical creatures.
Which is made even worse when she's rescued by an elf-who turns out to be the king's brother. He brings her into the forest to save her life. However, her healing comes with a cost-while the king permits Amber to be temporarily healed, he refuses to give her the full antidote until she agrees to bind with and strengthen the barrier around the elven wood, leaving her trapped in this new world. With no choice, she accepts.
However, Amber soon realizes that the Darkening Woods holds many secrets, not least the webs that the king is weaving. She and the far-too-handsome Eldrin must figure out how to survive the king's schemes-and their growing feelings for each other-before the king decides she's no longer worth saving and the poison kills her after all.