Question: How many novels did the detective who helped Antoinette Marceau on the Murder on the Orient Express appear in?

Context paragraphs:
Orient Express (board game): Orient Express is a crime fiction board game published by Jumbo and Just Games.  The game is based on the book "Murder On the Orient Express" by Agatha Christie.  The game was designed by Jeff Smets and released in 1985.  The game contains 10 different murder cases, each of which can be played only once.  Five new plots were released in 1987.

Orient Express (1954 film): Orient Express is a 1954 Italian-language film starring Silvana Pampanini, Henri Vidal, Folco Lulli, Eva Bartok and Curd Jürgens.  The plot revolves around a two-day stop at a village in the Alps by passengers on the Orient Express.

Jacqueline Bisset: Winifred Jacqueline Fraser Bisset ( ; born 13 September 1944) is an English actress.  She began her film career in 1965 and first came to prominence in 1968 with roles in "The Detective", "Bullitt", and "The Sweet Ride", for which she received a most promising newcomer Golden Globe nomination.  In the 1970s, she starred in "Airport" (1970), "Day for Night" (1973) which won the Academy Award for Best Foreign Language Film, "Murder on the Orient Express" (1974), "The Deep" (1977), and "Who Is Killing the Great Chefs of Europe? " (1978), which earned her a Golden Globe nomination as Best Actress in a Comedy.

Murder on the Orient Express (2001 film): Murder on the Orient Express is a 2001 made-for-television movie, based on the 1934 novel "Murder on the Orient Express" by Agatha Christie, featuring Hercule Poirot.  This version is set in the present day and has a smaller cast than the novel.  The original music score was composed by Christopher Franke.

Murder of Christie Marceau: On 7 November 2011, eighteen-year-old Christie Alexis Lesley Marceau ( , born 16 April 1993) was stabbed to death by eighteen-year-old Akshay Anand Chand (born 11 November or 11 December 1992) at her home in Hillcrest, Auckland, New Zealand.  The murder came after Chand had kidnapped and assaulted Marceau in September 2011, and while awaiting trial on the charges, was bailed by the court to an address just 300 m from Marceau's home, despite calls from Christie and the police to not grant bail.  Chand was subsequently charged with Marceau's murder, but on 17 October 2012 was acquitted of her murder by reason of insanity.  He was subsequently sentenced to three years imprisonment for kidnapping, and was committed to a psychiatric hospital indefinitely.

Stamboul Train: Stamboul Train (1932) is the second significant novel by Graham Greene.  Set on an "Orient Express" train, that ran from Ostend, Belgium to Istanbul, Turkey, the book was renamed Orient Express, when it was published in the United States.  Greene in fact wrote three books before this one, but two were unsuccessful and he later disowned them, "The Name of Action" (1930) and "Rumour at Nightfall" (1932).  "Stamboul Train" (1932) was Greene's first true success and it was taken on by the Book Society and in 1934 adapted as the film "Orient Express".

Hercule Poirot: Hercule Poirot ( ; ] ) is a fictional Belgian detective, created by Agatha Christie.  Poirot is one of Christie's most famous and long-lived characters, appearing in 33 novels, one play ("Black Coffee"), and more than 50 short stories published between 1920 and 1975.

Agatha Christie: Murder on the Orient Express: Agatha Christie: Murder on the Orient Express is a 2006 adventure game developed by AWE Productions and published by The Adventure Company for Microsoft Windows.  It is the second installment in The Adventure Company's "Agatha Christie series".  The setting is five years before the events in "", with a largely unrelated storyline.  The plot follows an amateur sleuth, Antoinette Marceau, and her investigation of a murder with twelve possible suspects aboard the Orient Express, which has been blocked by an avalanche in the Kingdom of Yugoslavia during 1934.  She is aided by famous detective Hercule Poirot.

Orient Express (1943 film): Orient Express is a 1943 Hungarian drama film directed by László Cserépy and starring Andor Ajtay, Irén Pelsöczy and Gyula Csortos.  It is based on a play by Andor Matolcsy about events taking place on the "Orient Express".

Murder on the Orient Express: Murder on the Orient Express is a detective novel by Agatha Christie featuring the Belgian detective Hercule Poirot.  It was first published in the United Kingdom by the Collins Crime Club on 1 January 1934.  In the United States, it was published on 28 February 1934, under the title of "Murder in the Calais Coach," by Dodd, Mead and Company.  The U.K. edition retailed at seven shillings and sixpence (7/6) and the U.S. edition at $2.00.

Supporting paragraphs: Agatha Christie: Murder on the Orient Express Hercule Poirot
Answer: 33