Question: Who wrote the 2007 British television film "Coming Down The Mountain" and authored a 2003 mystery novel based on Arthur Conan Doyle's short story "Silver Blaze"?

Context paragraphs:
Sherlock Holmes (2010 film): Sir Arthur Conan Doyle's Sherlock Holmes, also known simply as Sherlock Holmes, is a British-American 2010 steampunk mystery film directed by Rachel Lee Goldenberg and produced by independent American film studio The Asylum.  It features the Sherlock Holmes characters created by Sir Arthur Conan Doyle, though it follows an original plot.  The film details an unrecorded case in which eccentric detective Holmes and his companion Dr. Watson investigate a series of unusual monster attacks and a plot to destroy London.  Gareth David-Lloyd plays Dr. John Watson and Ben Syder, making his film debut, plays Sherlock Holmes.

The Curious Incident of the Dog in the Night-Time: The Curious Incident of the Dog in the Night-Time is a 2003 mystery novel by British writer Mark Haddon.  Its title quotes the fictional detective Sherlock Holmes in Arthur Conan Doyle's 1892 short story "Silver Blaze".  Haddon and "The Curious Incident" won the Whitbread Book Awards for Best Novel and Book of the Year, the Commonwealth Writers' Prize for Best First Book, and the Guardian Children's Fiction Prize.  Unusually, it was published simultaneously in separate editions for adults and children.

The Adventure of Silver Blaze: "Silver Blaze", one of the 56 Sherlock Holmes short stories written by British author Sir Arthur Conan Doyle, is one of 12 in the cycle collected as "The Memoirs of Sherlock Holmes".  Doyle ranked "Silver Blaze" 13th in a list of his 19 favourite Sherlock Holmes stories.

The Lost World (TV series): Sir Arthur Conan Doyle's The Lost World is a syndicated television series loosely based on the 1912 novel by Sir Arthur Conan Doyle, "The Lost World".  The show premiered in the United States in the fall of 1999 (after the TV-movie/pilot aired in February on DirecTV and then on the cable television channel TNT in April), it ran for three seasons before it was cancelled on a cliffhanger in 2002 after funding for a fourth season fell through.  To this day, the cliffhanger remains unresolved.  All three seasons were released in DVD box sets in 2004.

Silver Blaze (1977 film): Silver Blaze is a 1977 British/Canadian television film directed by John Davies and starring Christopher Plummer and Thorley Walters.  It is based on Arthur Conan Doyle's story of the same name.

Adrian Conan Doyle: Adrian Malcolm Conan Doyle (19 November 19103 June 1970) was the youngest son of Sir Arthur Conan Doyle and his second wife Jean, Lady Doyle or Lady Conan Doyle.  He had two siblings, sister Jean and brother Denis, as well as two half-siblings, sister Mary and brother Kingsley.

Dead Man's Land: Dead Man's Land is a book by Robert Ryan, based in World War I.  It involves Sherlock Holmes' sidekick, Dr. Watson (created by Arthur Conan Doyle).  It is fully authorized by Conan Doyle Estate Ltd. "Dead Man' Land" has been written under license from the Sir Arthur Conan Doyle literary Estate

Coming Down the Mountain: Coming Down the Mountain is a 2007 British television film which was shown on BBC One, written by Mark Haddon (author of "The Curious Incident of the Dog in the Night-Time") and directed by Julie Anne Robinson.  The television film was based on a radio play also written by Haddon.

The Return of Sherlock Holmes (1929 film): The Return of Sherlock Holmes is a 1929 American Pre-Code mystery film directed by Basil Dean and written by Arthur Conan Doyle, Basil Dean and Garrett Fort.  The film shares its title with the third volume of the Sherlock Holmes stories, "The Return of Sherlock Holmes" by Arthur Conan Doyle.  The film stars Clive Brook, H. Reeves-Smith, Betty Lawford, Charles Hay and Phillips Holmes.  The film was released October 29, 1929, by Paramount Pictures.  A copy is held at the Library of Congress.

Silver Blaze (1937 film): Silver Blaze is a 1937 British, black-and-white crime and mystery film, based loosely on Arthur Conan Doyle's short story "Silver Blaze".  It was directed by Thomas Bentley, and was produced by Twickenham Film Studios Productions.  It stars Arthur Wontner as Sherlock Holmes, Ian Fleming as Dr. Watson and Ronald Shiner (uncredited) as Simpson the Stable Boy/Jockey.  In the United States the film was released in 1941 by Astor Pictures, where it was also known as Murder at the Baskervilles, retitled by distributors to capitalize on the success of the Basil Rathbone Holmes film, "The Hound of the Baskervilles".

Supporting paragraphs: Coming Down the Mountain The Curious Incident of the Dog in the Night-Time
Answer: Mark Haddon