Lens of Time (Book 16 of Silver Wood Coven) - Hazel Hunter - Bog

Betrayal comes from where the team least expects it.Though the last of the Fae crystals have slipped from their grasp, Summer, Michael and Troy cannot give up the quest. Returned to the present day and stunned by what they find, they make one final attempt to save the world from the destruction. But as they close in on the impossible goal, they are not alone.