Claude Opus 4.8 vs GPT-5.5 for book writing

The letters shouldn't exist.

They arrive addressed to Edith Brand's sister — dead for forty years — postmarked from a village that no longer exists, drowned beneath a reservoir since 1971.

Retired and haunted, Edith returns to the place she once called home, renting a room above the pub from a landlord whose memory runs deeper than the water. But the further she wades into the past, the murkier her sister's death becomes. Was it an accident? A tragedy of her own making? Or something darker, long buried?

Some secrets don't stay drowned.

And…

Retired lighthouse keeper Edith Brand thought she had buried the past—until letters addressed to her dead sister begin arriving, postmarked from the village they once called home. But that village was drowned beneath a reservoir in 1971.

Drawn back to the shoreline of memory, Edith rents a room above the local pub, where the landlord knows more than he should and silence runs deep. Forty years after her sister’s death, Edith must uncover what really happened—before the secrets beneath the water rise again.