Question: Christopher Mitchell starred in a film based on a novel by what author?

Context paragraphs:
Here We Go Round the Mulberry Bush (film): Here We Go Round the Mulberry Bush is a 1967 British film made based on the novel of the same name by Hunter Davies.  It was listed to compete at the 1968 Cannes Film Festival, but the festival was cancelled due to the events of May 1968 in France.

The Dogs of War (film): The Dogs of War is a 1980 war film based upon the 1974 novel of the same name by Frederick Forsyth.  Largely filmed in Belize, it was directed by John Irvin and starred Christopher Walken and Tom Berenger.  In it a small mercenary unit of soldiers is privately hired to depose the president of a fictional African country so that a British tycoon can gain access to a platinum deposit.

Monsieur (1990 film): Monsieur is a 1990 comedy film based on the 1986 novel of the same name by Jean-Philippe Toussaint.  It was directed by the novel's author and produced by Pascal Judelewicz and Anne-Dominique Toussaint.  The film starred Dominic Gould, Wojciech Pszoniak, and Eva Ionesco.  "Monsieur" was screened at the 1990 Toronto International Film Festival.  It received the André Cavens Award for Best Film given by the Belgian Film Critics Association (UCC).

Magicians (2007 film): Magicians is a 2007 British comedy film released on 18 May 2007.  It stars comic duo Robert Webb and David Mitchell as stage magicians Karl and Harry.  The two magicians compete together in a magic competition, despite their personal differences.  Parts and ideas of the film have been taken to parody the 2006 film "The Prestige" by Christopher Nolan, though this had not been released when "Magicians" was filmed (though the original novel by Christopher Priest had been published in 1995).  The film is directed by Andrew O'Connor and written by Jesse Armstrong and Sam Bain, who are also the writers of the Channel 4 sitcom "Peep Show", which stars Mitchell and Webb.  Other principal cast members include Jessica Hynes, Darren Boyd, Steve Edge, Peter Capaldi, and Andrea Riseborough.

Firefox Down: Firefox Down is a 1983 novel by author Craig Thomas.  It is a sequel to his novel "Firefox".  Craig Thomas dedicated the first edition of the novel to actor/director/producer Clint Eastwood, who starred as Mitchell Gant in the film adaptation of the first novel, stating, "For Clint Eastwood — pilot of the Firefox".

The Call of the Wild (1976 film): The Call of the Wild is a 1976 American television film based on Jack London's 1903 novel "The Call of the Wild".  The film, starring John Beck, was directed by Jerry Jameson from a script by the poet and novelist James Dickey.  One of several adaptations of London's novel, this version was produced following the success of the 1972 film "Deliverance", an adaptation of Dickey's novel of the same title.  The author's son, Christopher Dickey, wrote in his 1998 memoir, "Summer of Deliverance", that "[t]he Hollywood concept [for the 1976 film] was James Dickey meets Jack London; sort of "Deliverance" in the Klondike."

The Light in the Forest (film): The Light in the Forest is a 1958 film based on a novel of the same name first published in 1953 by U.S. author Conrad Richter.  The film was produced by Walt Disney Productions and starred Fess Parker, Joanne Dru, James MacArthur, and Wendell Corey.  Though it is a work of fiction and primarily features fictional characters, the novel incorporates several real people and facts from U.S. history.

What's Up Superdoc!: What's Up Superdoc!  is a 1978 British sex comedy film, directed by sexploitation director Derek Ford and produced by Michael L. Green.  The film was a sequel to the 1977 film "What's Up Nurse! ", with Christopher Mitchell replacing Nicholas Field as the oversexed Dr. Todd.  The cast included Harry H. Corbett, Hughie Green, and a brief appearance by sex film star Mary Millington.

Christopher Mitchell (actor): Christopher Mitchell (21 May 1947 – 22 February 2001) was a British actor most notable for his role in the BBC sitcom "It Ain't Half Hot Mum" as Gunner Nigel 'Parky' Parkin.  His film credits include "Here We Go Round the Mulberry Bush" (1967), "This, That and the Other" (1969), "The Sex Thief" (1973) and "What's Up Superdoc! " (1978).

What's Up Nurse!: What's Up Nurse!  is a 1977 British sex comedy film directed by sexploitation director Derek Ford.  It stars Nicholas Field, Felicity Devonshire and John Le Mesurier, and tells the story of the adventures of a young doctor in a hospital.  A sequel "What's Up Superdoc! " was released the following year, with Christopher Mitchell replacing Nicholas Field as Dr Todd.

Supporting paragraphs: Christopher Mitchell (actor) Here We Go Round the Mulberry Bush (film)
Answer: Hunter Davies