The implantation surgeries for the twenty selected individuals were carried out systematically in the biological laboratory deep within the Dorne Spear fortress.
Unlike traditional Astartes reconstruction surgery, which requires multiple surgical interventions and lasts for several years, Osiris adopted a simplified new procedure.
The laboratory was filled with the unique atmosphere of mechanical engineering.
The silver-gray metal walls are covered with data interfaces and pipes flowing with coolant, while multiple adjustable robotic arms hang from the ceiling, their ends equipped with various precision surgical tools.
Several large arrays of Thinkers lined the wall, emitting a continuous low-frequency hum as they processed the massive amounts of data generated during the surgery.
The air was filled with a mixture of smells from disinfectants, ozone, and nutrient solutions.
The twenty candidates have been transferred here and are lying flat on the neatly arranged surgical platforms under deep anesthesia.
Each person's vital signs are displayed in real time by the connected monitoring equipment, and the data stream scrolls smoothly on the adjacent screen.
Osiris's massive mechanical body stood in front of the central control console in the laboratory, with multiple slender mechanical tentacles extending from his back and hovering above the surgical area, ready to perform delicate operations at any time.
Sigismund stood in the observation gallery, gazing down at the scene through the thick glass curtain wall.
He noticed that there were no large number of invasive instruments such as bone saws and large thoracotomy machines commonly used in traditional Space Marine surgery. Instead, there were more precise and less invasive devices.
The surgical procedure was indeed quite different from the standard procedure that Sigismund knew.
There are no large incisions that require almost completely opening the patient, nor are there organ removals and implantations that last for hours or even days.
The mechanical tentacles made a 15-centimeter incision in the center of the subject's chest, precisely separating the tissues and exposing the area behind the sternum.
Subsequently, a novel genetic seed sealed in a specially made container was extracted.
The mechanical tentacles implanted the gene seed at a predetermined location—behind the sternum, close to the mediastinum—with extremely high stability.
This location avoids most important blood vessels and nerve plexuses, but can still establish an effective connection with the circulatory and nervous systems through minimally invasive techniques.
Thin bio-wires, as fine as a hair, are precisely connected to key nodes in the carotid artery and vagus nerve.
The entire implantation process took about thirty minutes, after which the incision was quickly sutured, leaving only a faint scar.
"Is that all?" Sigismund asked through the communication channel, his voice carrying a barely perceptible hint of doubt.
The transformation process he was familiar with was far more complex and lengthy than this.
"The core implantation phase is complete," Osiris's synthesized voice responded. "The seed is in place, and the connection has been established. The subsequent development process will proceed under controlled conditions."
Once implantation was completed, the recipients were transferred to a culture area on the other side of the laboratory.
Here are twenty cylindrical culture tanks, made of transparent reinforced glass, filled with a pale green nutrient solution.
The tank is connected to a complex life support system and monitoring equipment.
The recipients were carefully placed into the canisters, and the interface wires were connected to the implantation points on their chests.
"They will spend the next twelve months under continuous anesthesia," Osiris explained to Sigismund. "During this period, they will complete two key processes: memory infusion and physiological development."
Each culture vessel is equipped with a sophisticated neural interface that connects directly to the subject's brain.
This system will instill in the chosen ones the vast amount of knowledge necessary to be an Astartes monk with an efficiency far exceeding the natural learning speed of the human brain—including advanced tactical theories, various alien biological characteristics, operation manuals for complex weapon systems, in-depth interpretations of Imperial history and doctrine, and the traditions and combat etiquette of each chapter.
"The previous three months of training only laid the foundation for their basic discipline and physical fitness, allowing them to initially adapt to the Astartes' behavioral patterns," Osiris explained. "If they were to rely on traditional teaching methods to master all the necessary knowledge, even with the Astartes' learning ability, it would take more than ten years."
Memory transfer technology can compress this process to within one year.
Meanwhile, the nutrient solution inside the culture tank contains specific growth-inducing factors and bioactive catalysts.
These ingredients will stimulate the selected individuals' bodies to develop rapidly, increase muscle density, restructure and strengthen bones, and boost metabolic rate to extraordinary levels.
This ripening technology, based on bioalchemy, was originally used to rapidly cultivate biochemical slaves or specific biological components for the Mechanicus.
"The accelerated physiological development and memory infusion proceed simultaneously, ensuring that they reach the baseline requirements of Astartes in both body and mind when they awaken," Osiris added. "This is essentially the application of the same biotechnology in another field."
Sigismund observed in silence.
He saw the nutrient solution inside the culture tank begin to circulate, with tiny bubbles rising from the bottom of the tank.
The monitoring screen showed that the participants' vital signs—heart rate, brainwave activity, and metabolic level—were beginning to show the expected changes.
One or two of the participants experienced slight, unconscious twitching, a normal reaction as the neural interface begins to function.
"How stable is this method?" Sigismund asked.
He noted that Cesare's culture tank data showed particularly active neural activity, while Groom's physiological indicators were unusually stable.
Carcus' readings showed a high stress response, even under anesthesia.
"The theoretical model predicts a success rate of 96.4%," Osiris replied. "The actual data will be updated after this batch of subjects completes. Compared with traditional methods, this method significantly reduces the mortality rate and risk of complications during the surgical phase."
As the last selected candidate—a young man from Necromunda—was placed into the culture tank and the system connection was completed, the main lighting in the laboratory was gradually dimmed, leaving only the indicator lights needed for the equipment to operate.
Twenty culture tanks emitted a soft fluorescence in the dim light, and the figures inside floated slightly in the nutrient solution.
"The development process has officially begun," Osiris announced. "The system will enter an automated operation state. They will complete their transformation within the next twelve months."
Sigismund gave the row of culture tanks one last look.
He knew that a year later, what would emerge from these jars would either be twenty new Astartes or twenty failed specimens that needed to be disposed of.
He had seen both outcomes many times during the empire's long conquests.
He turned and left the observation corridor, the sound of his power armored footsteps echoing through the metal passageway.
The laboratory door slowly closed behind him, isolating twenty dormant destinies from the outside world.
Osiris' mechanical body still stands in front of the control panel, the faint light of the culture tank reflected in the optical lens, and the data stream slides silently along its edge.
The year-long developmental timeline has begun.