AYes. The movie is based on the novel 4.50 from Paddington by British crime writer Dame Agatha Christie [1890-1976]. The screenplay is credited to David Osborn, David Pursall, and Jack Seddon.
AYes, many. Margaret Rutherford starred as Miss Jane Marple in three more Agatha Christie movies: Murder at the Gallop (1963), Murder Most Foul (1964), and Murder Ahoy (1964). In the mid-1980s and early 1990s, Joan Hickman (who played Mrs Kidder in this movie) starred as Miss Marple in a series of TV movies collectively titled 'Agatha Christie's Miss Marple'. These included Agatha Christie's Miss Marple: A Murder Is Announced (1985), Agatha Christie's Miss Marple: At Bertram's Hotel (1985), Agatha Christie's Miss Marple: The Moving Finger (1985), Agatha Christie's Miss Marple: Sleeping Murder (1987), Agatha Christie's Miss Marple: A Pocket Full of Rye (1987), Agatha Christie's Miss Marple: 4.50 from Paddington (1987), Agatha Christie's Miss Marple: A Caribbean Mystery (1989), Agatha Christie's Miss Marple: They Do It with Mirrors (1991), and Agatha Christie's Miss Marple: The Mirror Crack'd from Side to Side (1992). In the 2000s, Geraldine McEwan played Miss Marple in another series of TV movies collectively titled 'Agatha Christie Marple', including Agatha Christie's Marple: The Murder at the Vicarage (#1.2) (2004), Agatha Christie's Marple: The Body in the Library (#1.1) (2004), Agatha Christie's Marple: A Murder Is Announced (#1.4) (2005), Agatha Christie's Marple: Sleeping Murder (#2.1) (2006), Agatha Christie's Marple: By the Pricking of My Thumbs (#2.3) (2006), and Agatha Christie's Marple: Ordeal by Innocence (#3.2) (2007).Julia McKenzie then took on the role in Agatha Christie's Marple: A Pocket Full of Rye (#4.1) (2008), Agatha Christie's Marple: Murder Is Easy (#4.2) (2008), and Agatha Christie's Marple: Why Didn't They Ask Evans? (#4.4) (2009). Others to play Miss Marple in TV movies include Helen Hayes in A Caribbean Mystery (1983) and Murder with Mirrors (1985) as well as Angela Lansbury in The Mirror Crack'd (1980). Lansbury went on to star as Jessica Fletcher in the TV series 'Murder, She Wrote' (1984-1996). While not featuring Miss Marple, the series is a titular nod to Christie's Murder She Said.
AJust before bedtime, Jane has Dr Quimper stop by her room to check on her sore throat. She purposely leaves the compact laying on the table in full view. Quimper comments on the compact then examines her throat and neck. Jane calls his attention to a mirror in which his hands on her throat can be seen and informs him that she's seen his hands like this before on another woman's throat. She describes her belief that he gave the compact to someone -- probably his wife -- then killed her, wrote the letter supposedly from Martine in order to cast suspicion on the Ackenthorpea, then murdered Albert and Howard...all in an attempt to marry Emma and share in her inheritance. As Quimper is about to inject Jane with something to induce heart failure, Inspector Craddock (Charles 'Bud' Tingwell) and Sergeant Bacon (Gordon Harris) step out from behind a curtain and nab Quimper. The case finally solved, Jane gives notice and visits Luther to say goodbye. She is most surprised when he asks her to marry him, but she politely refuses. In the final scene, Jim drives Jane away from Ackenthorpe Hall in his car, to which Alexander has tied shoes and added a sign saying, 'Just married.'
