It is Christmas afternoon and Peter Martin gets an unexpected phonecall from his parents, asking him to come round. It pulls him away from his wife and children and into a bewildering mystery. He arrives at his parents' house and discovers that they have a visitor.
His sister Tara.
Not so unusual you might think, this is Christmas after all, a time when families get together. But twenty years ago Tara took a walk into the woods and never came back and as the years have gone by with no word from her the family have, unspoken, assumed that she was dead. Now she's back, tired, dirty, dishevelled, but happy and full of stories about twenty years spent travelling the world, an epic odyssey taken on a whim.
But her stories don't quite hang together and once she has cleaned herself up and got some sleep it becomes apparent that the intervening years have been very kind to Tara. She really does look no different from the young women who walked out the door twenty years ago. Peter's parents are just delighted to have their little girl back, but Peter and his best friend Richie, Tara's one time boyfriend, are not so sure.
Tara seems happy enough but there is something about her. A haunted, otherworldly quality.
Some would say it's as if she's off with the fairies.

And as the months go by Peter begins to suspect that the woods around their homes are not finished with Tara and his family...