One Across, Two Down is a psychological suspense novel by British writer Ruth Rendell.

[1] In 1976, it was made into the film, Diary of the Dead by Arvin Brown, written by I.C.

Stanley Manning is a fortysomething petrol-station attendant and hobbyist crossword puzzler who lives with his wife, Vera, and mother-in-law, Maud.

Maud is a controlling elderly woman who despises Stanley as a ne’er-do-well, based partly on his conviction prior to meeting Vera for mugging an old woman.

They make Vera's life unhappy as they bicker every day, but on learning that Maud has £20,000 (£284,825 as of 2019, per inflation) due in her will to Vera, Stanley plans to deal with Maud once and for all by interfering with her medication.