This is a good episode, though I have to agree with one poster, that the solution came out of left field.
Barnaby and Troy are called in to investigate a car fire -- thankfully, there were no injuries. However, murders do occur: First, there's the murder of an elderly woman who is found bludgeoned in her home. The victim, Marjorie Empson, ran a reading club, which was really a front for five village women to invest in the stock market. It turns out that two members wanted to cash out but were voted down.
Then a second member of the club is killed.
Barnaby and Troy find adultery, unhappy marriages, a woman trying to handle her hypochondriacal husband, a pool man who seems too handy, and people receiving mysterious packages that indicate that someone knows their secrets.
Market for Murder is an enjoyable episode, with Troy indulging in his secret love for a childhood hero, The Hawk, buying the latest edition of his story. (Can he fly? asks Barnaby. Only when he's a hawk, Troy says.) And Barnaby is worrying about his pension which seems to be with a shaky company.
In order to make the end a little more satisfying, the script needed some shoring up. It's still pretty good.