In this heartwarming, bookish debut, a young widower of a famous children's fantasy author teams up with a down-on-her-luck MFA dropout to write the final book in his late wife's series...and find their own perfect ending along the way.Whit Longacre has a monumental task and a looming deadline. After his wife, Helen, died of cancer, she left him with their grieving eight-year-old daughter and a surprise in her will: the small task of writing the final book in her mega-popular children's fantasy series for her legions of waiting fans.Whit is the author of moderately successful (but well-received!) literary mysteries. He doesn't have the first idea of how to complete Helen's beloved series, and his enigmatic wife seems to have left no clues behind on how the story is supposed to end. Writer's block is one thing, but to fail in fulfilling his wife's last wish? Whit is guilt-ridden and dodging calls in the school pick-up line from Helen's publisher and agent as the deadline fast approaches.Then Whit meets Merritt Pryor, who works at the local bookstore in their small New England town. Merritt has moved back home after a disastrous affair led to her dropping out of her prestigious MFA program. When Whit realizes that Merritt is a superfan of the Greenwood Castle series, they come up with a plan to tackle the book together. For the first time in years, Merritt finds herself falling back in love with writing...and perhaps with the coauthor offering her the opportunity of a lifetime.But when Whit uncovers a buried secret about Helen's final wishes, he questions everything about what he and Merritt have created together, endangering the tender, electrifying partnership that has transformed their lives.Can Whit and Merritt come up with an ending that feels right...for both a beloved series and for their battered hearts?