Peter Guillam is a fictional character in John le Carré's series of espionage novels. He first appears in Call for the Dead at which time he is working for the Ministry of Defence, and later appears in The Spy Who Came in From the Cold.

In the novel Tinker, Tailor, Soldier, Spy in which he is a principal character, Guillam is head of "Scalphunters", the violent division of 'The Circus' (MI6) that deals with operations such as assassination, blackmail, burglary, and kidnapping. He took over the division after the failure of Operation Testify led the former section head Jim Prideaux to leave the Circus. In the aftermath of Testify's failure, the division's importance was downgraded, and being in charge of it was considered a menial position. It was looked down upon even by Guillam's friend George Smiley, who jokingly describes the division's operations as "cosh and carry".

Nevertheless Guillam is the key in finding the mole, or traitor, within the Circus. When one of his subordinates resurfaces after disappearing, claiming to have information about the mole, Guillam alerts Oliver Lacon, the Civil Service overseer of the Intelligence Service. This bypasses the "inner circle", in Guillam's direct line-of-command, who have squelched any previous suggestions of a mole. Lacon and Guillam then seek the return of Smiley - who had been dismissed by the Circus following Testify - to secretly lead an ivestigation of the inner circle to find the mole. During Smiley's subsequent investigations, Guillam covertly provides helpers, and himself steals information from within the Circus's registry.

Zachary John Quinto (born June 2, 1977) is an American actor and producer. Quinto grew up in Pennsylvania and was active in high school musical theater. In the early 2000s, he guest starred in television series and appeared in a recurring role in the serial drama 24 from 2003 to 2004. In 2006, Quinto acted in the sitcom So NoTORIous and portrayed series antagonist Sylar in the science fiction drama Heroes from 2006 to 2010. He was cast as Spock of the Star Trek franchise and appeared in the 2009 reboot Star Trek. He will continue the role in the 2013 sequel. He also voiced the Emergency Medical Hologram (EMH) in the Star Trek Online MMORPG

Quinto, who is of half-Italian and half-Irish descent, was born in Pittsburgh and grew up in Green Tree, Pennsylvania, with his mother Margo and his brother Joe. His father, John, who was a barber, died of cancer when Quinto was 7 years old. He graduated from Central Catholic High School in 1995, where he participated in their musicals and won the Gene Kelly Award for Best Supporting Actor, and then attended Carnegie Mellon University's School of Drama, from which he graduated in 1999.

Benedict Timothy Carlton Cumberbatch (born 19 July 1976) is an English film, television, radio and theatre actor. His most acclaimed roles include Stephen Hawking in the BBC drama Hawking (2004); William Pitt in the historical film Amazing Grace (2006); the protagonist Stephen Ezard in the miniseries thriller The Last Enemy (2008); Paul Marshall in Atonement (2007); Bernard in Small Island (2009); Sherlock Holmes in the modern BBC adaptation series Sherlock (2010); and Peter Guillam in the spy thriller Tinker Tailor Soldier Spy (2011).

In February 2011, he began playing both Victor Frankenstein and his creature opposite Jonny Lee Miller in Danny Boyle's stage adaptation of Mary Shelley's Frankenstein. The play had a three-month run at the National Theatre. In late 2011, he played Major Stewart in Steven Spielberg's War Horse (2011). The film received five BAFTA nominations and six Academy Award nominations, including the Best Picture nomination in 2012. He also played Peter Guillam, one of the pivotal roles in Tomas Alfredson's Tinker, Tailor, Soldier, Spy (2011), which was nominated for three Academy Awards and 11 BAFTA Awards. Tinker Tailor Soldier Spy was also nominated for Best Picture in 2012.

Cillian Murphy  /ˈkɪliən/ (born 25 May 1976) is an Irish film and theatre actor. He is often noted by critics for his chameleonic performances in diverse roles and his distinctive blue eyes.

A native of Cork, Murphy began his performing career as a rock musician. After turning down a record deal, he made his professional acting debut in the play Disco Pigs in 1996. He went on to star in Irish and British film and stage productions throughout the late 1990s and early 2000s, first coming to international attention in 2003 as the hero in the post-apocalyptic film 28 Days Later. Murphy's best-known roles are as villains in two 2005 blockbusters: Scarecrow in the superhero film Batman Begins (a role later reprised as a cameo in The Dark Knight), and Jackson Rippner in the thriller Red Eye. Next came two contrasting and acclaimed starring roles: his Golden Globe Award-nominated performance as a glam transgender orphan teen in 2005's Breakfast on Pluto and a turn as a 1920s Irish revolutionary in the 2006 Palme d'Or winner, The Wind That Shakes the Barley. In 2010, Murphy played the target of Leonardo DiCaprio's dreamscape heist in the acclaimed blockbuster Inception.

Sherlock Holmes ( /ˈʃɜrlɒk ˈhoʊmz/) is a fictional detective created by Scottish author and physician Sir Arthur Conan Doyle. The fantastic London-based "consulting detective", Holmes is famous for his astute logical reasoning, his ability to adopt almost any disguise, and his use of forensic science skills to solve difficult cases.

Holmes, who first appeared in publication in 1887, was featured in four novels and 56 short stories. The first novel, A Study in Scarlet, appeared in Beeton's Christmas Annual in 1887 and the second, The Sign of the Four, in Lippincott's Monthly Magazine in 1890. The character grew tremendously in popularity with the first series of short stories in Strand Magazine, beginning with A Scandal in Bohemia in 1891; further series of short stories and two novels published in serial form appeared between then and 1927. The stories cover a period from around 1880 up to 1914.

All but four stories are narrated by Holmes's friend and biographer, Dr. John H. Watson; two are narrated by Holmes himself ("The Blanched Soldier" and "The Lion's Mane") and two others are written in the third person ("The Mazarin Stone" and "His Last Bow"). In two stories ("The Musgrave Ritual" and "The Gloria Scott"), Holmes tells Watson the main story from his memories, while Watson becomes the narrator of the frame story. The first and fourth novels, A Study in Scarlet and The Valley of Fear, each include a long interval of omniscient narration recounting events unknown to either Holmes or Watson.