A small force of mostly American troops, mercenaries under a secret CIA contract in Africa during the Cold War about to be annihilated by a Cuban military force, is "rescued" by the Shalnuksis, extraterrestrial beings part of an interstellar Confederation who offer them their lives in exchange for service on a primitive planet raising surinomaz ("madweed"), a plant used to produce a recreational drug.
The series of novels describe how these 20th-century soldiers proceed to both integrate with the existing cultures on Tran and use them to establish a base of operations for growing and harvesting of the surinomaz plant, which only becomes sufficiently potent for use as a recreational drug for a couple of decades out of every 600 Earth years.
The first book shows how the soldiers use a combination of modern weaponry, knowledge of technology, and advanced military tactics to carve out a political enclave that will enable them to fulfill the rest of their mission, to raise the madweed they are expected to provide to the extraterrestrials who brought them to Tran.
As the mercenaries learn more of the history of Tran, it also becomes clear that they will eventually be betrayed by their benefactors, as this has been the fate of each generation of imported soldiers in turn.
Their leader, Rick Galloway, begins to plan how they, and more important, the knowledge they have brought to Tran, will survive that betrayal, which involves the Shalnukskis using atomic bombs to destroy the areas of the planet controlled by the mercenaries.
There are local legends of sky gods who bring gifts, but always take them back again; dragons melting a city with skyfire (a tapestry in the Great Hall of a castle prominently features this); and taboo places, including a lake with a glass bottom.
At the same time, forces beyond their control and of which they have no knowledge begin to plan for what appears to be a possible revolt of all humans in the Confederation, which would have drastic consequences for Earth.
But it was reported in December 2018 that Jerry's son Phillip was in the second draft of Mamelukes working with American selling science fiction and fantasy author David Weber as editor.
On 15 November 2019 Jerry's View from Chaos Manor was updated with the news that Mamelukes (Janissaries 4) was finished, and it was published in hard cover on 2 June 2020.