Vacancy follows the main character
Talin, the building manager of Aldergate House, a mid-century co-living building where an ever-present AI called Warden quietly manages residents lighting, comfort, and memory "for their wellbeing."
Talin has worked in Aldergate House longer than any tenant has ever stayed there, and she's stopped trusting anything she can't write down by hand.
In the Pilot episode:
"Room 4B", Talin asks Warden about a vacant unit "4B" only to find her own notebook holds a memory of a tenant Warden insists never existed. Is Talin losing her grip on reality, or is the building rewriting it?