Alice Stern isn't ready to turn forty. She thought she'd have more time to figure it all out. Above all, she thought she'd have more time with her father, Leonard - but he's lying in a hospital bed and Alice isn't sure if she'll hear his voice again.

When she falls asleep outside their old apartment on the night before her birthday, she's surprised to be greeted the next morning by a much younger Leonard, with a sixteenth birthday card for a teenage Alice who, far from clinging to her youth, is hurtling towards adulthood . . .

Alice soon discovers how she got back here, to 1996 and her sixteenth birthday, and realises she can keep on coming, whenever she chooses.

But faced each time with different versions of her life, and the consequences of her decisions, it's on her not to lose sight of what she wants most . . .