You've spent your career trusting documents more than memory. Memory lies, edits itself, smooths the rough edges. But documents hold whatever was true the day they were signed.

Until you find the one that shouldn't exist.

Notary Fotini Ralli has authenticated thousands of signatures in her twelve years serving the small town of Kyparissia. She knows the weight of ink on paper, the tremor that betrays age, the confident strokes of youth. She can spot a forgery from across the room.

But the 1987 property deed stops her cold. Two witness signatures. Same name. Same hand. Forty years of aging between them—both authenticated on the same day by her predecessor, who left only a cryptic log entry: 'I witnessed what I witnessed.'

The investigation leads to Vangelis Stratos, a solitary olive farmer whose left hand has been trembling for six weeks—ever since the fortieth anniversary of a promise he thought he'd forgotten. To an abandoned house on the hill where lights appear in the study window at exactly 11:47 PM, though the power was cut in 1987. To documents that record impossible truths and carbon copies that remember what the originals haven't yet received.

Some signatures bind more than property. Some promises echo through decades, creating loops in time itself that only a witness can close.

The mathematics of the impossible await your signature.