I will admit that I wasn't grateful: invalids so rarely are. I think I said something along the lines of "Oh, no, not a book of the television series. I can't stand those." I hope I was gracious enough to apologise when I realised that W J Burley created Inspector Wycliffe in 1966, but I doubt it. He's had a few promotions since then (Wycliffe, that is - Mr Burley was the senior Biology master at a school in Newquay before he became a full-time writer) and he's now Chief Superintendent.
There is a story progression throughout the series of books, but each can be read on its own without any problems, with the exception of ''Wycliffe and the Guild of Nine'' which contains a spoiler for an earlier book. If you did want to begin at the beginning, so to speak, then the first novel is ''Wycliffe and the Three-Toed Pussy'']] and there's a list of the novels in chronological order [http://www.booksnbytes.com/authors/burley_wj.html#QS787 here].
"Wycliffe and the Dunes Mystery" (first published in 1993) is number 20 of the 22 novels, but don't let that put you off reading it. Back in 1977 six young people slope off for a weekend of fun and frolics at a seaside property owned by one of the parents. Whilst they're there a young man, Cochran Wilder happens by and he's never seen again.