In this reality-bending thriller from the author of The Shining Girls, a grieving daughter's search for her mother becomes a journey across alternate realities.

It was a game they played; the other worlds, the other lives. It was part of her mom's grand delusions. It wasn't real. Unless it was...
Bridget Kittinger has always been paralyzed by choices. It has a lot to do with growing up in the long shadow of her mother, Jo, a troubled neuroscientist. Jo's obsession with one mythical object, the "dreamworm"—which she believed enabled travel to other worlds—led to their estrangement.
Now, suddenly, Jo is dead. And in packing up her home, Bridge finds a strange device buried deep in Jo's freezer: the dreamworm. Against all odds, it actually can open the door—to all other realities, and to all other versions of herself, too. Could Bridge find who she should be in this world, by visiting the others? And could her Jo still be alive somewhere? But there's a sinister cost to trading places, and others hunting the dreamworm who would kill to get their hands on it . . .
Across a thousand possible lives, from Portland to Haiti, from Argentina to the alligator-infested riverways of North Carolina, Bridge takes readers on a highly original thrill ride, pushing the boundaries of what we know about mothers and daughters, hunters and seekers, and who we each choose to be.