Leading expert Gavin Mortimer tells the remarkable origin story of a wartime special forces unit that defied the odds. Z Special Unit, one of the most intrepid but arguably the most unsung of Allied Special Forces of the Second World War waged a guerrilla war against Japan for two years in the south-west Pacific. On some of their 81 operations Z Special Unit slipped into enemy harbours in canoes and silently mined ships before vanishing into the night; on others they parachuted into the dense Borneo jungle to fight with headhunters against the Japanese and on one occasion they landed on an Indonesian island and smuggled out the pro-Allied sultan from under Japanese noses. The Japanese weren't the only adversary that Z Special Unit encountered in the brutal terrain of the Pacific. In the mango swamps of Borneo and the dense jungle of Papua New Guinea they were faced with venomous snakes, man-eating crocodiles and deadly diseases. But it was the enemy soldiers who proved the most ruthless foe, beheading those Z Special Unit commandos who fell into their hands. Drawing on veteran interviews as well as operational reports and recently declassified SOE files, Gavin Mortimer explores the incredible history of this remarkable special forces unit and the band of commandoes that defied the odds.

March 1945. A handful of young Allied operatives are parachuted into the remote jungled heart of the Japanese-occupied island of Borneo, east of Singapore, there to recruit the island’s indigenous Dayak peoples to fight the Japanese. Yet most have barely encountered Asian or indigenous people before, speak next to no Borneo languages, and know little about Dayaks, other than that they have been – and may still be – headhunters. They fear that on arrival the Dayaks will kill them or hand them over to the Japanese. For their part, some Dayaks have never before seen a white face. So begins the story of Operation Semut, an Australian secret operation launched by the organisation codenamed Services Reconnaisance Department – popularly known as Z Special Unit – in the final months of WWII. Anthropologist Christine Helliwell has called on her years of first-hand knowledge of Borneo, interviewed more than one hundred Dayak people and all the remaining Semut operatives, and consulted thousands of military and other documents to piece together this astonishing story. Focusing on the operation's activities along two of Borneo’s great rivers – the Baram and Rejang – the book provides a detailed military history of Semut II’s and Semut III’s brutal guerrilla campaign against the Japanese, and reveals the decisive but long-overlooked Dayak role in the operation. But this is no ordinary history. Helliwell captures vividly the sounds, smells and tastes of the jungles into which the operatives are plunged, an environment so terrifying that many are unsure whether jungle or Japanese is the greater enemy. And she takes us into the lives and cavernous longhouses of the Dayaks on whom their survival depends. The result is a truly unique account of the encounter between two very different cultures amidst the savagery of the Pacific War.

Account of Australia's Z Special Unit's missions behind Japanese lines during the period 1942-45. It is a story about the courage, danger and initiative of the individuals and small groups who had little hope of help if their missions were unsuccessful. Contains an honour roll of members killed on active service, a bibliography and an index.

Soon after the declaration of war on Japan, a secret military reconnaissance unit was established, based on the British Special Operations Executive (known as SOE) and called the Inter-allied Services Department. The unit was tasked with the role to "obtain and report information of the enemy ... weaken the enemy by sabotage and destruction of morale and to lend aid and assistance to local efforts to the same end in enemy occupied territories." In 1943 it became known under the cover name Special Reconnaissance Department (SRD) and included some British officers who had escaped from Singapore. After arriving in Australia, they assembled in Melbourne, forming the nucleus of ISD and together with some Australians established what became the Z Special Unit. Training began in a number of locations around Australia including on Fraser Island off the Queensland coast, In Broken Bay near Sydney, at Careening Bay in Western Australia, at the “House on the Hill” in Cairns and at East Arm near Darwin. From these training areas and bases, Z Special undertook intelligence gathering and raiding missions throughout Southeast Asia including New Guinea, Singapore, Timor, Malaya, Borneo, Vietnam and the Dutch East Indies. The first operation was Jaywick in September 1943. Led by a 28 year old officer from the Gordon Highlanders, Captain Ivan Lyon. Using an old Japanese fishing boat renamed Krait this captured vessel was re-fitted and provisioned for a voyage from Australia to just south of Singapore where it released six commandos in three folding kayaks to attack Japanese shipping in the harbour. They placed limpet mines on several Japanese ships sinking 40,000 tons of shipping. After the successful attack, they paddled south, were picked up by the Krait and successfully returned to Australia. This was followed by Operation Rimau again led by Lyon but this time things went very wrong very early. Identified, they made a fighting withdrawal but all of the raiding party were shot or captured, with the last ten being executed just before the end of the war. Important in Z Special operations were a number of vessels designated “snake boats”. Four 66’ modified trawlers were constructed as well as a range of Asian vessels that allowed their operation in South East Asian areas of operation. One Z Special, the last in PNG, set out on the night of the 11 April 1945. Eight operatives were landed on the Japanese held island of Muschu about five kilometres off the coast near Wewak to determine the status of two 140mm Japanese naval guns that had been placed there. These guns would prove dangerous to planned naval landings at Wewak, and allied command needed to know if these were operational. The operatives were launched in four double folding kayaks from a HTML fast crash boat but the current carried them away from their landing position and the surf capsized their boats. The men swam ashore but both their radio and their signal torches had been destroyed and the men had no way of connecting with the return crash boat. Soon their lost equipment was found by the Japanese and a massive search with 1,000 troops scoured the island. Quite soon seven of the eight men had been captured, killed or died trying to swim to the mainland and only one man, Sergeant ‘Mick’ Dennis remained. Over the next three days he continued a one man war, fighting off Japanese patrols and living off the land. Unable to do this for long, he took to the dangerous shark and crocodile infested waters and with the aid of a log, paddled to the mainland. Landing on a Japanese controlled beach, he snuck ashore and after further firefights and a difficult journey travelling west, he finally was found by an Australian patrol. Mick Dennis was able to provide valuable information and for his service and bravery, was awarded a Military Medal. During the course of the war, Z Special Unit carried out 81 covert operations in the Southwest Pacific theatre. While the unit was disbanded after the end of the war, many of its techniques would be modified and used by Australian Special Forces to this day.