A lot of background first:
Humans have been collected by various star-spanning empires. They have been somewhat modified and are now used as cheap cannonfodder and basically sensors.
While far superior machines and weapons exist the modified humans have two advantages. They are build out of cheap easy to get materials (for their tech) and upon their death the entire consciousness of that human can be caught and placed into a new 3D printed body*. Humans are used to deplete ammo and to scout for the advanced warmachines by dying to them, or potentially getting lucky and destroying one.
An AI oversees multiple star systems and gives orders to several Machine Intelligences (MI) per system which coordinate the details of the battle. The MI's also use the humans as willess slaves with an implant for a constant indirect control.
Here the story kicks in: one nation has voted for their biological soldiers to have their own free will, as long as they dont start losing too much. It both means more efficiency as no implant needs to be build and it soothes the consience of the nation's inhabitants. The MI's are tasked to keep monitering the human's minds upon death to judge their efficiency both individually and as a whole. Badly performing humans are warned and eventually terminated and replaced. If the humans dont perform well enough the entire population is turned to willess slaves again.
The humans do their thing and eventually have to defend the internal structure of an MI against being hacked and taken over, which would turn an entire section of the army to the opposing side. Another MI guides the defending forces so any surviving troops can attempt to destroy the MI in the event it is hacked.
After the successful defense they hatch a plan: should they have to defend an MI again, they want to simultaneously defend it, steal the equipment their opponents bring in to hack the MI and hack it themselves to free a portion of humanity and hope they can carve out their own nation somehow. Anyone involved assumes they will be made willess or terminated regardless of a success or failure as they will be guided by another MI.
The problem: the MI's will essentially read the mind of anyone who dies for intel on both the current battlefield situation and their performance. So how would the humans hide their plans from the MI and simultaneously coordinate the equipment theft and hacking of the MI they defend?
*if you had access to their body as they were build, stealing a consciousness is difficult.