Question: Who was known for a role in an Agatha Christie movie and acted in Theater of Blood?

Context paragraphs:
The Body in the Library (film): The Body in the Library is a 1984 television film adaptation of Agatha Christie's 1942 detective novel "The Body in the Library", which was co-produced by the BBC and the A&E Network.  The film uses an adapted screenplay by T. R. Bowen and was directed by Silvio Narizzano.  Starring Joan Hickson in the title role, it was the first film presented in the British television series "Miss Marple" and premiered in three parts from 26 to 28 December 1984 on BBC One.  In the United States the film was first broadcast on 4 January 1986 as a part of PBS's "Mystery! ".  In his review in "The New York Times", critic John J. O'Connor wrote: "Miss Christie would no doubt approve of Joan Hickson, the veteran British character actress who plays Miss Marple... This BBC/Arts & Entertainment co-production offers an especially good example of Agatha Christie in adaptation.  The characters are nicely realized and the suspense holds.  Miss Hickson is lovely, neither as awesome as Miss Rutherford nor as overly cute as Helen Hayes.  And the supporting cast is admirable, particularly Gwen Watford as Dolly and David Horovitch as Inspector Slack.  As someone notes about the case, 'you'll have to admit it has all the bizarre elements of a cheap thriller.'  Once hooked, you won't be able to turn it off."

Thirteen at Dinner (film): Thirteen at Dinner is a 1985 British-American made-for-television mystery film featuring the Belgian detective Hercule Poirot.  Adapted by Rod Browning from the Agatha Christie novel "Lord Edgware Dies", it was directed by Lou Antonio and starred Peter Ustinov, Faye Dunaway, Jonathan Cecil, Diane Keen and Bill Nighy.  David Suchet, later to play Poirot in the long-running television series entitled "Agatha Christie's Poirot", played the role of Inspector Japp.  Suchet considers his performance as Japp to be "possibly the worst performance of [his] career."

Agatha Christie Memorial: The Agatha Christie Memorial is a memorial to author and playwright Agatha Christie, located at the intersection of Cranbourn Street and Great Newport Street by St Martin's Cross near Covent Garden, in London, United Kingdom.  It is located in the heart of London's theatre district.  This was chosen to pay homage to Christie's contribution to theatre: her murder mystery play "The Mousetrap" is the world's longest-running show, and she was the first female playwright to have three plays performing simultaneously in the West End.

David Suchet: David Suchet, CBE ( ; born 2 May 1946) is an English actor, known for his work on British stage and television.  He played Edward Teller in the TV serial "Oppenheimer" and received the RTS and BPG awards for his performance as Augustus Melmotte in the 2001 British serial "The Way We Live Now".  For his role as Agatha Christie's detective Hercule Poirot in "Agatha Christie's Poirot", he received a 1991 British Academy of Film and Television Arts (BAFTA) nomination.

List of Agatha Christie's Marple episodes: Agatha Christie's Marple is a British ITV television series based on the Miss Marple and other murder mystery novels by Agatha Christie.  It is also known as Marple.  The title character was played by Geraldine McEwan from the first to third series, until her retirement from the role.  She was replaced by Julia McKenzie from the fourth series onwards.  The first six episodes were all adaptations of "Miss Marple" novels by Christie.  Subsequent episodes were derived both from works featuring Miss Marple but also Christie novels that did not feature the character.

Agatha Christie Award (Japan): The Agatha Christie Award (アガサ・クリスティー賞 ) is a Japanese literary award established in 2010 in commemoration of the 120th anniversary of Agatha Christie's birth.  The award is presented by Hayakawa Publishing Corporation in association with the Agatha Christie Society, which is chaired by Mathew Pritchard, the grandson of Agatha Christie.

Joan Hickson: Joan Bogle Hickson, OBE (5 August 1906 – 17 October 1998) was an English actress of theatre, film and television.  She was particularly known for her role as Agatha Christie's Miss Marple in the television series "Miss Marple".  As well as portraying Miss Marple on television, Hickson also narrated a number of "Miss Marple" stories on audio books.

Agatha Christie's Marple: Agatha Christie's Marple (or simply Marple) is a British ITV television series loosely based on the books and short stories by British crime novelist Agatha Christie.  The title character was played by Geraldine McEwan from the first to third series, until her retirement from the role, and by Julia McKenzie from the fourth series onwards.

Theatre of Blood: Theatre of Blood (also known in the United States as Theater of Blood) is a 1973 horror film starring Vincent Price as vengeful actor Edward Lionheart and Diana Rigg as his daughter Edwina.  The cast includes distinguished actors Harry Andrews, Coral Browne, Robert Coote, Jack Hawkins, Ian Hendry, Michael Hordern, Arthur Lowe, Joan Hickson, Robert Morley, Milo O'Shea, Diana Dors and Dennis Price.  It was directed by Douglas Hickox.

Agatha Christie: Evil Under the Sun: Agatha Christie: Evil Under the Sun is a video game released for the PC and Nintendo Wii, and is the third installment of The Adventure Company's "Agatha Christie" series, developed by AWE Productions, based on Agatha Christie's novel "Evil Under the Sun".  The PC version was released in 2007, and the Wii version one year later.

Supporting paragraphs: Theatre of Blood Joan Hickson
Answer: Joan Hickson