The Thursday Murder Club by Richard Osman is a slow burner, I nearly put it down after the first few chapters but I soldiered on and it improved a bit.
Four friends living in a retirement community meet once a week to discuss unsolved murder cases (one never quite finds out why or how). Then a brutal murder takes place on their doorsteps and they manage to insert themselves into the case gradually unpicking the threads which go back almost 50 years.
The narrator is one of the 4 pensioner detectives and her voice is droll rather than funny. There are a couple of twists as the plot draws to a close but you are left with the feeling of clumsily strewn red herrings rather than gasping in surprise.
Maybe if I you like the Miss Marple series or watch Midsomer Murders you will enjoy this, but I thought it was a bit meh!