—This is your book of regrets —she says—. It contains every decision you lament. Every missed opportunity.

Nora feels a dizzying sensation in her stomach. She touches the cover with her fingers, and a flood of images overwhelms her mind. The band she left before signing a contract. The relationship she let wither. The university she never finished. Her brother, happier without her. Her mother, disappointed to her last breath.

Each page weighs like a stone.

—I don’t want to see more.

—Then it’s time to choose —Mrs. Elm says, pulling a book at random from the shelf—. This is a life where you became an Olympic swimmer. In this one, you never left the band. In this one, you married that boy you loved.

Nora swallows hard.

—If I step into one of these lives… what happens to the one I left behind?

—That life no longer exists —Mrs. Elm replies—. But if you find one that makes you happy… you can stay.

The idea is tempting. A reset. Erase every mistake, every regret.

Mrs. Elm hands her a book with a deep blue cover.

—Start with this one.

Nora takes it, closes her eyes, and opens it.