In Summerwood, twelve-year old Rosalind Hero Cheung can't wait to spend the summer in Toronto with her teenaged sister Julie and their famous author grandfather. Years ago Walter Denison wrote a series of bestselling children's novels about a magical land called the Summerwood. But to Hero's dismay, Walter is cold toward his granddaughters and Julie derides Hero's hope that the Summerwood is real.

Nevertheless one day she and Julie stumble into the Summerwood. Ruled by the beautiful and enigmatic Lady of Summer, it is the idyllic fantasy land out of Walter's books, complete with quaintly dressed talking animals. However, Hero discovers the Summerwood is far more sinister than Walter had ever let on. Julie is abducted and to save her life, Hero must find the Summerwood's sacred winter stag. Hero quickly learns that seeing out on a fantasy quest is far more prosaic and terrifying than she'd ever imagined, and there is a steep and bloody price to pay for being the hero.

In Winterwood, three years have passed since Lindy Cheung went into the Summerwood and emerged changed and broken. Now she's geting into trouble starting fights, skipping school, dating unsuitable boys. After her mother grounds her again she runs o to Toronto to her sister, the only person who knows what really happened three years ago. But Juliet has moved on from the trauma, and Lindsay finds herself back in the Summerwood, where an old enemy tells her: The stag must die again.

And this time, in order to save the Summerwood, she has to be the bad guy instead of the hero.