Claude Opus 4.8 vs Kimi K3 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…

Edith Brand spent forty years believing her sister's death was a tragedy. Then the letters started arriving — addressed to a woman long buried, postmarked from a village that no longer exists. Drowned beneath a reservoir in 1971, their childhood home should be silent. But someone is writing. Someone remembers. Edith returns to the valley, takes a room above the pub, and finds a landlord whose memory is dangerously good. The deeper she digs, the more certain she becomes: her sister's death was neither accident nor suicide. Some secrets were mean…