Doctor Palfrey is a spy, head of Z-5.  Dr Palfrey is a Physician of some reknown and is lured into an elite espionage world.  During the course of the stories the character goes through some transformation.  He is made second in command by the end of the war.  Although after the war he resumes his civilian life he is drawn back into action and becomes leader of the z-5.

Dr. Palfrey (Z5) series was written as John Creasey between 1942–1979

• Traitor’s Doom (November 1942)
• The Valley of Fear (May 1943)  a.p.a. The Perilous Country
• The Legion of the Lost (November 1943)
• Dangerous Quest (1944)
• Death in the Rising Sun (1945)
• The Hounds of Vengeance (1945)
• Shadow of Doom (1946)
• The House of the Bears (1946)
• Dark Harvest (1947)
• The Wings of Peace (1948)
• The Sons of Satan (1948)
• The Dawn of Darkness (1949)
• The League of Light (1949)
• The Man Who Shook the World (1950)
• The Prophet of Fire (1951)
• The Children of Hate (1952)  a.p.a. The Killers of Innocence
• The Touch of Death (1954)
• The Mists of Fear (1955)
• The Flood (1956)
• The Plague of Silence (1958)
• The Drought (1959) a.p.a. Dry Spell
• The Terror (1962)
• The Depths (1963)
• The Sleep (1964)
• The Inferno (1965)
• The Famine (1967)
• The Blight (1968)
• The Oasis (1969)
• The Smog (1970)
• The Unbegotten (1971)
• The Insulators (1972)
• The Voiceless Ones (1973)
• The Thunder-Maker (1976)
• The Whirlwind (1979)

Four additional Z5 stories have been written by the author’s son Richard; in these, the central figure is Thomas Palfrey, the doctor’s grandson.

• Eternity’s Sunrise (2012)
• Hard Targets (2013) an omnibus of three shorter adventures – “Wings of Fear,” “Burning Night,” and “Deadly Sleep”