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Chiselbury Publishing is to publish Who Dares Betray, a new wartime thriller by acclaimed military historian Gavin Mortimer, on 1 December 2026.
Set in occupied France in June 1944, Who Dares Betray plunges readers into the clandestine war fought behind enemy lines following D-Day. As Allied forces battle their way out of Normandy, a squadron of Special Air Service soldiers parachutes into central France with orders to disrupt German reinforcements moving north to counter the landings.
Operating deep inside hostile territory alongside the local Maquis, the SAS wages a ruthless guerrilla campaign of sabotage, ambush and assassination. But the greatest threat does not come from the enemy.
One of the soldiers is a traitor, turned by the Germans and now a committed Nazi. Embedded within the squadron, he is prepared not only to betray his comrades, but to kill them if necessary.
At first, the unit’s losses are blamed on the brutal unpredictability of war. Then one soldier dies in unexplained circumstances and another disappears without trace. As German patrols close in and trust begins to collapse, the SAS must identify the Judas in its ranks before he leads the enemy directly to their forest hideout.
Mortimer is one of Britain’s leading authorities on the wartime SAS and special operations warfare. Across more than thirty works of military and narrative history, he has drawn extensively on interviews with veterans of the SAS, SBS, Long Range Desert Group and other special forces units.
He also lives in the region of central France in which the novel is set, giving him an intimate knowledge of the landscape, villages and forests that shaped the SAS campaign of 1944. This combination of historical research, first-hand testimony and familiarity with the terrain gives Who Dares Betray an unusual degree of authenticity.
Stuart Leasor, publisher at Chiselbury, said:
“Few writers know the wartime SAS as Gavin does. His understanding extends beyond the operations themselves to the personalities, pressures and loyalties within small groups of men working in secrecy and constant danger. In Who Dares Betray, he has turned that knowledge into a tense and compelling thriller in which the enemy is not only closing in from outside, but is already within the unit.”
Mortimer’s next major work of non-fiction, The Real Rogue Heroes: The Wartime SAS in Their Own Words, will be published by Osprey in March 2027. Drawing on interviews with 75 original SAS veterans and previously unpublished private material, it will present the story of the wartime regiment through the experiences of the men who served in it.
Combining historical accuracy with mounting tension and moral complexity, Who Dares Betray explores loyalty, betrayal and survival in the unforgiving world of clandestine warfare. It will appeal to readers of military history and wartime thrillers, and to admirers of writers such as Jack Higgins, Len Deighton and Ken Follett.
Who Dares Betray will be published by Chiselbury Publishing in paperback and ebook on 1 December 2026 and is available to preorder now.
Publication date: 1 December 2026
Formats: Paperback and ebook
Paperback ISBN: 9781917837842
Publisher: Chiselbury Publishing
For further information, review copies or interview requests:
Stuart Leasor
Chiselbury Publishing
info@chiselbury.co.uk
www.chiselbury.co.uk
ABOUT GAVIN MORTIMER
Gavin Mortimer is a bestselling writer, historian and television consultant whose books have been published in Britain and the United States. He has written extensively about the SAS, SBS, Long Range Desert Group and other special forces units of the Second World War.
His books include Stirling’s Men, The Men Who Made the SAS, The SAS in Occupied France, 2 SAS and the critically acclaimed David Stirling: The Phoney Major. He has worked as a consultant on television documentaries and as an adviser to the National Army Museum and the Musée de la Libération de Paris.
He lives in central France.
www.gavinmortimer.com
X: @PhoneyMajor
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