Suffolk, 1962. The Devereux family are gathering for a party, and a series of anonymous letters are about to turn the sleepy village of Melstead St Mary upside down . . . Evelyn is preparing to celebrate her 20th wedding anniversary, but there are secrets she's never told her beloved husband, Kit. Secrets that stretch back to her wartime days at Bletchley Park . . . For Hope, her sister-in-law, happiness has never come easily, and the letter she receives could destroy her fragile world....