The problem is that under medieval conditions, there were no high-purity separation instruments, no autoclaves, no microbial freezers, no liquid nitrogen cylinders, and not even electricity. Naturally, neither of these two methods could be carried out.

As a second-best option, Todd planned to use the "subculture preservation method" and the "suspension preservation method".

The former is the oldest and most basic method of microbial preservation. The general procedure involves setting the culture temperature slightly below the optimal growth temperature, appropriately reducing the concentration of the culture medium, and transferring all bacteria every two days. The advantage of this method is that the bacteria are readily available; the disadvantages are that it is time-consuming, cumbersome, and highly susceptible to contamination.

The suspension preservation method is mainly for anaerobic bacteria. Depending on the characteristics of the bacteria, they are suspended in distilled water, sugar solution or phosphoric acid to maintain their properties. If stored properly, they can be preserved at room temperature for several years.

After nearly ten days, Todd finally finished preserving all the bacteria. Looking at the shelves full of petri dishes and suspensions, he could finally breathe a sigh of relief, with only one thought in his mind.

The prototype of the "Special Ability Library" has finally been completed. Although there are only more than twenty kinds of special abilities at present, just like a library, as the research and discovery of special abilities progresses, this microbial warehouse will eventually become larger and more complete. Perhaps one day, after discovering the hidden secrets of the special ability microorganisms, it will even be possible to improve or even artificially synthesize more powerful special abilities.

A knock at the door interrupted his thoughts.

After closing the door to the back room, Todd walked to the laboratory door, opened it, and saw Rachel waving a stack of papers in her hand, smiling as she said, "Commander-in-Chief, the test results for Mr. Randall are in. Would you like to hear them?"

Todd, who was standing at the door, stepped aside to make way for him and said, "Come in and we'll talk in detail."

Quite surprised, Rachel raised an eyebrow, lifted the hem of her wide nun's robe with one hand, and walked into the laboratory. Looking at the complex equipment and colorful solvents in the room, the woman remarked with a touch of emotion, "This is the first time I've been allowed to enter here."

Todd moved a chair over, wiped the dust off it with a dry cloth, and placed it in the middle of the laboratory.

Rachel watched his every move and, for some reason, suddenly thought of the relief party. The boy before her, dressed similarly, preferred to curl up in the deckchair, just to avoid rudely stretching his feet towards her.

Seeing the woman standing there, her gaze unfocused, Todd had no choice but to gesture for her to sit down.

"Tell me, has Mr. Randall passed the test? Is he suitable for the role of the alien hero?"

Rachel handed the paper to Todd, resting her chin on her hand, and said with some uncertainty, "You could say he passed, or you could say he didn't..."

Todd looked up from the paper, then looked up at the woman, his face full of confusion: "Why do you say that?"

"Without a doubt, he has an extremely strong sense of justice. Faced with evil and injustice, he has never considered personal gain or safety; he always steps forward to help..."

Listening to Rachel's words, Todd became increasingly puzzled: "Isn't this exactly what we need?"

The woman curled the cross on her chest with her fingers, glancing to the side: "But his fighting style and mindset are unacceptable. It's a life-or-death struggle, never heeding the enemy's swords or his own wounds. In one test, my men were nearly driven to pierce Mr. Randall's heart by this reckless fighting style. In my opinion, it's less like fighting and more like pursuing self-destruction..."

Todd flipped through the 'test report' compiled by the woman, growing increasingly alarmed with each reading. To save an elderly couple who had encountered 'robbers,' this guy had acted like a madman in the fight, charging at six enemies with his sword. Despite being stabbed and slashed countless times, he didn't back down until he collapsed from exhaustion.

"I want to see him."

Hearing this, Rachel gave Todd a meaningful look and asked, "Commander-in-Chief, in what capacity do you intend to meet Mr. Randall?"

Todd put down the paper, looked at the woman and smiled: "Miss Rachel, there is a priest who hopes to guide lost sheep."