Actress Marieanne Kray and producer Toby Taylor are at Arlington Grange to make a film about its former owner, George Velares.

Several residents know Toby or Marieanne (under her real name, Maisie Medford). Scarlet has been deceived into a ""casting couch"" affair with Toby, believing she had been offered the role in the Velares film which he in fact gave to Marieanne... Mustard knew Velares and now understands how he died. Marieanne and Elizabeth Peacock were once in a theatre company together, and Elizabeth believes Marieanne poisoned her to get a leading role from her... while Peter Plum thinks Marieanne stole his film script on the story of Velares. Marieanne, meanwhile, is thinking of writing her memoirs, in which she plans to tell all about an old affair with Jonathan Green.

Who is the murderer, and why?