In the novel Evil Under the Sun, Emily Brewster is an athletic spinster staying at the Jolly Roger Hotel. As part of an exercise routine, she went rowing every morning. Patrick Redfern joined her in her boat and they rowed to Pixy Cove where they discovered the body of Arlena Marshall.
A first cousin of Emily Brewster was married to a relation of Sir Robert Erskine, which give her some personal connection to the Arlena Marshall. Sir Robert had died and left Arlena Stuart most of his fortune, disinheriting his relatives. Emily Brewster therefore held a resentment toward Arlena on behalf of the Erskine Family.
Miss Brewster is described as being a "tough athletic woman with grizzled hair and a pleasant weather-beaten face". When talking to Mrs Gardener, who provides "a ceaseless flow of conversation", Miss Brewster makes "gruff comments". According to Poirot, she has a voice like a man's. He says that she rows boats and has a handicap of four at golf. Poirot also thinks that she has a good heart.
In the hotel register, Miss Brewster's address is given as Southgates, Sunbury-on-Thames.
Miss Brewster is afraid of heights, and states that she would not be able to go down the ladder to Pixy Cove. She also experiences giddiness when crossing a narrow plank bridge over a river.
On the morning of the murder, Miss Brewster goes for a morning dip before breakfast, and someone throws a bottle from one of the hotel windows, narrowly missing her. She later goes for a row with Patrick Redfern, and at his suggestion, they start to row right around the island, going ashore at Pixy Cove.
Upon seeing Arlena lying on the beach, Miss Brewster feels that something is wrong. She realizes that this is because Arlena is lying in the attitude of a sunbather, but there is no sun on the beach at that time, and there will not be for several more hours. She also notes the "curious unnatural angle" of the arms, and feels that the body had not lain down, but had been thrown.
Miss Brewster leaves in the boat, to notify the police. Although she would never admit to feeling fear, she is relieved that she does not have to stay on the beach with the "faint possibility of a homicidal maniac lingering close at hand".
Miss Brewster feels "unwilling sympathy" for Patrick Redfern, when she sees him sitting by Arlena's body. However, she has "robust common sense", and so believes that this is the best thing that could have happened for Patrick and Christine Redfern, as well as Captain Marshall and his daighter, Linda.
Miss Brewster tells the police that it was exactly a quarter to twelve when they found the body, and that they had rounded the point and seen the body lying on the beach about five or six minutes earlier.
She later tells Poirot, Colonel Weston and Inspector Colgate about a young man who had been involved with Arlena, and had done something "rather fishy" with shares to get more money to spend on her. According to Miss Brewster, this man was just able to escape prosecution.
Evil Under the Sun (1982)
Agatha Christie's Poirot
In ITV's 2001 adaptation of the novel, Emily Brewster is portrayed by Carolyn Pickles. Here she also has a plausible, but slightly different motive. She told Poirot that she would be "happy to stick a hat pin in her". A year ago, she had invested some money in a play in which Arlena Marshall starred. After the first performance, Arlena had walked off the production. As a result Emily lost all her money. Nonetheless, as in the original, here Emily Brewster also has an alibi as she was rowing with Patrick Redfern when the body of Arlena was discovered.
Les Petits Meurtres d'Agatha Christie
In Ding Dingue Dong, the France Télévisions adaptation of Evil Under the Sun, the parallel character is is actually the hardly athletic Marlène Leroy. Here she is suffers from an attack of depression and is admitted to the psychiatric clinic (the Jolly Roger Hotel parallel). The only similarity between her and Emily Brewster is that she is also used by the Patrick Redfern parallel Nathan Steiner to create an alibi and she comes upon the murder victim together with him.