In the spring of 1628, young Bess Hawksmith watches her mother's body swing limp from the Hanging Tree. She knows that only one man can save her from the same fate - Gideon Masters, the Warlock. She knows, too, that his help comes at a steep price.

In present-day England, Elizabeth has built a quiet life for herself. She has spent the centuries in solitude, moving from place to place, surviving plagues, wars and the heartbreak that comes with immortality. Her loneliness comes to an abrupt end when she is befriended by a teenage girl called Tegan. Against her better judgement, Elizabeth opens her heart to Tegan and begins teaching her the ways of the Hedge Witch.

But Gideon is hunting her still. He will stop at nothing, determined even after centuries to claim her soul. And now, Bess is not fighting to save herself alone: now, she must protect the girl she has grown to love like a daughter.