Ten years ago, Zelda led a band of merry adventurers whose knacks let them travel to alternate realities and battle the black rot that threatened to unmake each world. Zelda was the warrior; Ish could locate people anywhere; Ramon always knew what path to take; Sarah could turn catastrophe aside. Keeping them all connected: Sal, Zelda’s lover and the group's heart.

Until their final, failed mission, when Sal was lost. When they all fell apart.

Ten years on, Ish, Ramon, and Sarah are happy and successful. Zelda is alone, always traveling, destroying rot throughout the US.

When it boils through the crack in the Liberty Bell, the rot gives Zelda proof that Sal is alive, trapped somewhere in the alts.

Zelda’s getting the band back together—plus Sal’s young cousin June, who has a knack none of them have ever seen before.

As relationships rekindle, the friends begin to believe they can find Sal and heal all the worlds. It’s not going to be easy, but they’ve faced worse before.

But things have changed, out there in the alts. And in everyone's hearts.