A woman embarks on a virtual wellness retreat in order to get her life back on track but with nightmarish consequences.

In a near future of bad air and lives lived online, Carol (Elizabeth Banks) is strained inside a marriage she still wants, to Gary (John C. Reilly). She signs up for DreamQuil, an A.I. wellness retreat meant to put her life back together. While she is gone, the company delivers Carol-Too, an identical mechanical double, to the family she left at home. Carol returns refreshed and ready to begin again. The double does not leave, and it will not stop until the real Carol is gone.