Mori and her friends live a normal life on Firefly Lane in their utopian community, Old Harmonie. In a world this safe and perfect, they've never had to question anything . . . never had to wonder about how their lives came to be. Until a new girl named Ilana moves in. She's so perfect that Mori and her friends are curious . . . Where exactly did Ilana come from, and why does she act so strange sometimes? When Ilana's secret is revealed, the kids on Firefly Lane must decide: is it finally time to start questioning the only world they've ever known?

In a stunningly imaginative story, critically acclaimed author Megan Frazer Blakemore takes readers on a journey with five friends--new and old--that will have everyone talking about not just what makes people human, but what makes them true friends.