Allison runs away and, in what she thinks is an abandoned house, finds a home with Marla, an elderly woman with dementia who believes her to be an old friend named Toffee.

In a barren future world, the company known as Breathe has saved humanity by manufacturing glass domes and oxygen rich air. Outside the domes there is nothing, not even oxygen. Three teens--Alina, a thief; Quinn, a teen looking for romance with the girl of his dreams, the description of which fits Alina; and Bea, the girl who had hoped Quinn would notice her--take a journey into the Outlands, with enough oxygen for two days. What they find out there...

With little money or support, Joe Moon, seventeen, travels to Texas to help the older brother he barely knows through his last few weeks before being executed for murder.

Alina, Quinn, and Bea, now outlaws and outcasts, make their way to the last enclave of the Resistance but once there, they discover they can count on no one but each other and may, in fact, have to betray those they considered allies.