Spy Line is a 1989 spy novel written by British writer Len Deighton.
 It is the second novel in the second of three trilogies about Bernard Samson, a middle-aged and somewhat jaded intelligence officer working for the British Secret Intelligence Service (MI6).
 "Spy Line" is part of the "Hook, Line and Sinker" trilogy, being preceded by "Spy Hook" and followed "Spy Sinker".
 This trilogy is preceded by the "Game, Set and Match" trilogy and followed by the final "Faith, Hope and Charity" trilogy.
 Deighton's novel "Winter" (1987) is a prequel to the nine novels, covering the years 1900-1945 and providing the backstory to some of the characters.
Hope is a 1995 spy novel by Len Deighton.
 It is the second novel in the final trilogy of three about Bernard Samson, a middle-aged and somewhat jaded intelligence officer working for the British Secret Intelligence Service (MI6).
 "Hope" is part of the "Faith, Hope and Charity" trilogy, being preceded by "Faith" and followed by "Charity".
 This trilogy is preceded by the "Game, Set and Match" and the "Hook, Line and Sinker" trilogies.
 Deighton's novel "Winter" (1987) is a prequel to the nine novels, covering the years 1900-1945 and providing the backstory to some of the characters.
Faith is a 1994 spy novel by Len Deighton.
 It is the first novel in the final trilogy of three about Bernard Samson, a middle-aged and somewhat jaded intelligence officer working for the British Secret Intelligence Service (MI6).
 "Faith" is part of the "Faith, Hope and Charity" trilogy, being followed by "Hope" and "Charity".
 This trilogy is preceded by the "Game, Set and Match" and the "Hook, Line and Sinker" trilogies.
 Deighton's novel "Winter" (1987) is a prequel to the nine novels, covering the years 1900-1945 and providing the backstory to some of the characters.
Spy Hook is a 1988 spy novel by Len Deighton.
 It is the first novel in the second of three trilogies about Bernard Samson, a middle-aged and somewhat jaded intelligence officer working for the British Secret Intelligence Service (MI6).
 "Spy Hook" is part of the "Hook, Line and Sinker" trilogy, being succeeded by "Spy Line" and "Spy Sinker".
 This trilogy is preceded by the "Game, Set and Match" trilogy and followed by the final "Faith, Hope and Charity" trilogy.
 Deighton's novel "Winter" (1987) is a prequel to the nine novels, covering the years 1900-1945 and providing the backstory to some of the characters.
The Secret Intelligence Service (SIS), commonly known as MI6, is the foreign intelligence service of the government of the United Kingdom, tasked mainly with the covert overseas collection and analysis of human intelligence (HUMINT) in support of the UK's national security.
 SIS is a member of the country's intelligence community and its Chief is accountable to the country's Foreign Secretary.
Berlin Game is a 1983 spy novel by Len Deighton.
 It is the first novel in the first of three trilogies about Bernard Samson, a middle-aged and somewhat jaded intelligence officer working for the British Secret Intelligence Service (MI6).
 "Berlin Game" is part of the "Game, Set and Match" trilogy, being succeeded by "Mexico Set" and "London Match", and followed by the "Hook, Line and Sinker" trilogy and the final "Faith, Hope and Charity" trilogy.
 Deighton's novel "Winter" (1987) is a prequel to the nine novels, covering the years 1900-1945 and providing the backstory to some of the characters.
Mexico Set is a 1984 spy novel by Len Deighton.
 It is the second novel in the first of three trilogies about Bernard Samson, a middle-aged and somewhat jaded intelligence officer working for the British Secret Intelligence Service (MI6).
 "Mexico Set" is part of the "Game, Set and Match" trilogy, being preceded by "Berlin Game" and followed by "London Match".
 This trilogy is followed by the "Hook, Line and Sinker" trilogy and the final "Faith, Hope and Charity" trilogy.
 Deighton's novel "Winter" (1987) is a prequel to the nine novels, covering the years 1900-1945 and providing the backstory to some of the characters.
Spy Sinker is a 1990 spy novel by Len Deighton.
 It is the final novel in the second of three trilogies about Bernard Samson, a middle-aged and somewhat jaded intelligence officer working for the British Secret Intelligence Service (MI6).
 "Spy Sinker" is part of the "Hook, Line and Sinker" trilogy, being preceded by "Spy Hook" and "Spy Line".
 This trilogy is preceded by the "Game, Set and Match" trilogy and followed by the final "Faith, Hope and Charity" trilogy.
 Deighton's novel "Winter" (1987) is a prequel to the nine novels, covering the years 1900-1945 and providing the backstory to some of the characters.
London Match is a 1985 spy novel by Len Deighton.
 It is the concluding novel in the first of three trilogies about Bernard Samson, a middle-aged and somewhat jaded intelligence officer working for the British Secret Intelligence Service (MI6).
 "London Match" is part of the "Game, Set and Match" trilogy, being preceded by "Berlin Game" and "Mexico Set".
 This trilogy is followed by the "Hook, Line and Sinker" trilogy and the final "Faith, Hope and Charity" trilogy.
 Deighton's novel "Winter" (1987) is a prequel to the nine novels, covering the years 1900-1945 and providing the backstory to some of the characters.
Bernard Samson is a fictional character created by Len Deighton.
 Samson is a middle-aged and somewhat jaded intelligence officer working for the Secret Intelligence Service (SIS) – usually referred to as "the Department" in the novels.
 He is a central character in three trilogies written by Deighton, set in the years 1983–1988, with a large gap between 1984 and 1987.
 The first trilogy comprises the books "Berlin Game", "Mexico Set" and "London Match", the second comprises "Spy Hook", "Spy Line" and "Spy Sinker", and the third and final trilogy comprises "Faith", "Hope" and "Charity".
 The plot of the entire trilogy of trilogies revolves around Samson's wife Fiona, also an intelligence officer, and which side she is really working for, after she has defected to the East Germans in the first trilogy, leaving a distraught Bernard with their two children.
 Her defection also cause some of his superiors to question his loyalty.

Question: Spy Turk features a jaded intelligence officer employed by what service?
Answer: Secret Intelligence Service