Safe Return Doubtful

A young architect is sent to the dying, silted-up port of Cullerne to supervise long-overdue repairs to its Minster. But as he comes to know the town and its people, he finds himself caught up in a decades-old mystery. The late Martin Joliffe used to claim he was the real heir to Lord Blandamer’s estate, but he wasn’t taken seriously, and died before he could unravel the truth. When the next person to investigate the claim also dies suddenly there’s talk of a family curse, or maybe someone who doesn’t want the truth to get out.
There’s a lot going on here, and someone as unchurched as me could be initially put off by details of the Minster’s architecture, the church music and bells, but it would be wrong to be. This is a beguilingly and mysterious setting for a gothic tale wreathed in fog, damp and darkness; a richly atmospheric and very original mystery.
It is available as an ebook for free at Project Gutenberg.