Poison in the Pen written by Patricia Wentworth performed by Diana Bishop on Cassette (Unabridged)

Tilling Green was a charming little village nestling in the Ledshire countryside. Not at all the sort of place you would expect to find an anonymous letter writer. And when one of the recipients, a young woman, was found drowned in the lake belonging to the Manor House, Miss Silver was persuaded to go and investigate. Valentine Grey, the pretty young heiress from the Manor House, was marrying one Gilbert Earle, but on the night of Valentine's pre-wedding party Jason Leigh...

Valentine's former love, returned after months without a word. Valentine discovered Gilbert in a compromising situation with her guardian's wife. And several people received extremely nasty letters.

Connie Brooks knew who had written those letters. But on the same night, she was murdered...