A Fiend in Sprite's Clothing

Publisher's blurb: The party is travelling through the Gulthmere Forest on a road straight towards the rustic city of Cedarspoke. Their destination is still long away, and so they bed down for the night. When the awaken, they find that somehow they have been trapped in the Feywild. Oh no! An aging Treant is willing to help them, but only if they help him first. They must acquire a fruit from his youth, but they must beware. Among allied sprites, there is one that is secretly a murderer.