For as long as A can remember, life has meant waking up in a different person’s body every day, forced to live as that person until the day has ended. A always thought there wasn’t anyone else who was like this. A was wrong.

Someday starts where Every Day left off. David Levithan takes readers further into the lives of A and Rhiannon, exploring more deeply what Every Day and Another Day had originally asked: What is a soul? What makes us human? And does gender matter when it comes to love?