Helga Allowby, a self-described spinster, has been accused of sending noxious poison pen letters to the residents of her village - and she wants Hetty to prove her innocence. Hoping to penetrate the mistrust that pervades the village, Hetty goes undercover as Tara Hall, a visiting painter. When Hetty turns up next on the mailing list, she suspects that Miss Allowby is guilty of bad penmanship. (thetvdb.com)