The Spare Key Agreement

Carmen and Eli Brooks manage Harbor Brick by one rule: no apartment is entered without two people and a written log. The rule protects their tenants. It also protects their eleven-year marriage from the kind of silence that can turn access into control. Then Carmen finds an untagged brass key taped beneath their kitchen table. It opens a sixth-floor service door falsely labeled as a shallow riser panel-and an unauthorized archive of maintenance entries, staged photographs, tenant files, and quiet records of Carmen and Eli's daily lives.
The building's former owner still has enough access and influence to make every truthful step look like a violation. An old locksmith invoice forces Eli to reveal what he withheld years ago. Residents demand answers while Carmen and Eli struggle to preserve the evidence without claiming authority that belongs to the people documented inside it. To expose the archive, the couple must follow the agreement that their own marriage has failed to keep: disclose what they know, ask before entering, and accept that trust cannot be rebuilt in private.
Intimate, tense, and grounded in the working life of an old apartment building, The Spare Key Agreement is a domestic relationship thriller about surveillance, consent, accountability, and the difficult work of choosing trust again.