A serial killer stalks the agents of Department Z in a rip-roaring thriller from the Edgar Award–winning author who sold eighty million books worldwide. London, 1941. In the unending darkness of the London Blackout, an assassin slinks through the night, striking down victims with deadly accuracy. His targets are agents, killed while on watch. Department Z is baffled. Who is the silent killer, why is he targeting them, and what is their secret...

Department Z must stop the Nazis from deploying a deadly chemical weapon during World War II-from the author who sold eighty million books worldwide. On a top-secret island, the Germans are perfecting a paralyzing gas-one that could disable an entire infantry troop, a crew of a ship, or the pilots of aircraft. With the looming threat of this noxious gas, it's up to Department Z to find this mysterious island where the gas is being manufactured and...

Department Z faces its biggest test when the organization is threatened by an enemy on the inside-from the author who sold eighty million books worldwide. Charles Corliss, son of a murdered agent from Department Z, seems like the perfect recruit for the ultra-secret spy organization. But when things start going seriously wrong, the agents begin to suspect this charming young man is not as loyal as he first seemed. Filled with hate for the organization...

The greed of one man leads to the death of others in this action-packed mystery featuring British intelligence's secret detective squad. When two impossibly rich oil tycoons are found murdered in their own homes, a matter of life and death becomes one of national security. Jim Burke of Department Z is called in to stop this ambitious murderer from killing again-but it isn't long before Burke's investigation is derailed by an attempt on his own...

A mysterious message signals an international threat in this World War II thriller by an Edgar Award–winning author. A French refugee is washed up on the English coast. Feverish, delirious, he babbles incoherently to the men who find him. A single phrase, repeated: "Loftus, spell it backwards." This discovery sparks an explosive reaction throughout Department Z, whose agents-including Bill Loftus-are fighting a desperate battle to uncover...

The adventure that brought two intrepid cousins into the service of the department of British intelligence known as Z... Desperate to escape the suffocating heat of London, cousins Mark and Mike Errol set out for Richmond for a relaxing boat ride. Little did they know their peaceful afternoon would be violently interrupted by a Department Z mission that would completely change their lives. Quickly recruited into the secret agency, the Errols embark...

The detectives of Britain's Department Z look into a murder at an exclusive club. Sir Basil Riordon is mysterious, frightening, and immensely wealthy. But is he also a killer? As head of England's elite secret service, Department Z, Gordon Craigie has to find out, but it won't be an easy investigation with so many important people involved. A member of an exclusive London club has been poisoned, and Riordon or his son, Marcus, may be involved....

A suspenseful tale of murder and espionage in wartime England. David Garth has been off in America, giving speeches on behalf of Britain's Ministry of Propaganda. Upon his return, he's surprised to receive an unsigned invitation to an address in Wimbledon . . . and even more surprised when he's approached by two agents of Department Z. Mark and Mike Errol, agents of British intelligence's secret detective squad, request Garth's assistance on a mission...

Marius Krotz is notorious for his ability to cause a stir. A former revolutionary turned right-hand-man to the king of a small European country, he is feared as much for his unscrupulous manner as for his dangerous past. He's planning something big, and intelligence agencies across Europe have him in their sights. Department Z is on the case, led by the infamous Arran twins and new recruit Jim Burke, and this time they're pushed to their limits. Department...

In this classic spy thriller from an Edgar Award–winning author, a British secret service agency is nearly undone by a counter-espionage attack. Superspies are out to destroy Department Z. Even worse, the elite British agency has been infiltrated by a double agent. As loyal members of the team turn against one another, Agent Gordon Craigie works to unmask the counterspy before Department Z is annihilated once and for all.