Notes: I originally posted this fic under an old account between December 30, 2004 and October 1, 2005.

CH 1 - Antibodies

-x-

Haibara stared.

The rats were dead. All of them were dead.

"My God, what have I done?" Haibara Ai asked in a whisper and opened the cage.

That wasn't supposed to happen. Among the rats that were given the APTX-4869, most had died while a few had returned to their infancy. Those that were killed by APTX-4869 weren't too surprising - Haibara had expected that to happen. But for those that had returned to their infancy, Haibara had then given them the antidote to APTX-4869. They should've transformed back to their adult forms. Yet now, they were all dead.

When the results of the blood tests came in, Haibara shuddered. Once again, nothing out of the ordinary stood out from the test results for the rats killed by APTX-4869. For the few that took the antidote, however, Haibara discovered that there were virtually no white blood cells in the blood samples. No white blood cells, no antibodies; no antibodies, decreased efficiency in the immunity. Thus, the rats that took the antidote died from the germs they carried on their bodies.

Gripping the pieces of paper printed with the test results, Haibara sank into her chair and shut her eyes. Her jaws tightened. It was four o'clock in the morning and she had rushed into the lab in the basement of Doctor Agasa's house to test the antidote she thought she had found. She hadn't even bothered to change out of her pajamas. However, the outcome greeting her wasn't the success of finding the antidote for APTX-4869, but the shock from creating another killer drug.

Haibara picked up the test tube containing the small amount of green-powdered drug she had created and stared at it. Under the illumination of the dim light in the lab, the powder seemed to glow like the glow-in-the-dark stickers. The antidote was in the green powder; the powder was the extreme form of the antidote.

On this thought, Haibara calmed down a little. She closed her eyes again and let her thoughts wander.

It was a week ago when she began making the antidote.

Doctor Agasa had caught the flu going around town. Besides the only time that she could flop down on the sofa to rest for a couple minutes, Haibara was rushing back and forth, getting tissues, medicine, water, and all kinds of things needed to take care of and amuse a ridiculous flu patient.

By ridiculous, Haibara meant the things Doctor Agasa had said when he was sick and in bed:

"Don't you like the tissue box mountain I've made, Ai-kun?"

"I am Rudolf, the red-nose reindeer. Ouch, my nose hurts... I think I've blown it too much."

"Ai-kun! Bring me some dihydrogen monoxide! Cough!"

To all these, Haibara never responded. In fact, she was surprised that they even made an impression in her memory.

Because Haibara couldn't spend time in the lab during the time Doctor Agasa was ill, she had learned to conduct thought experiments on finding the antidote while going in and out of Doctor Agasa's room. It helped. It was like when a person had been thinking too much or too hard, a random string of words could cause something to click in the person's mind and solve whatever the person had been thinking about.

That day, Conan had come over with a new box of medicine. Haibara was pouring a cup of water for Doctor Agasa when Doctor Agasa complained about the failure the medicine was in curing his flu. Conan replied that the medicine only relieved the symptoms and that it was up to one's antibodies to kill the viruses.

"Something must be killing my antibodies then, if I'm recovering so slowly," Doctor Agasa responded.

When Haibara heard this, she paused and placed the bottle and the cup of water onto the table beside Doctor Agasa's bed. Then she rushed out of the room and to the lab, leaving Doctor Agasa and Conan, who had been explaining about the impact that old age had on the production speed of antibodies, puzzled.

That was it. APTX-4869 caused the cells to self-destruct, or, if lucky, to degenerate, as with Haibara Ai and Edogawa Conan. Paikaru, the Chinese liquor, contained the ingredients to reverse the effects of APTX-4869, but the human body produced antibodies against the toxin from Paikaru, rendering the reverse effect temporary. If she could make a counter agent that destroyed the antibodies before the antibodies neutralized the toxicity of Paikaru, the transformation of the cells back to the adult form should become permanent.

It made sense to Haibara. It was probably not the best way to find an antidote for APTX-4869, but it might work.

Yet it didn't. The effects of the counter agent went overboard - the green powder Haibara had made destroyed all white blood cells instead of the antibodies specific to the antigens from Paikaru.

Haibara poured the green powder into a red-and-white capsule and examined it. The few grams of powder were all that she was going to make, ever. People killed by APTX-4869, although the poison remained undetectable in the blood samples, would still be known to the police as murdered victims. Whereas for this green powder, the doctors, let alone the police, and even the relatives and family members, would dismiss the death as a result of severe illness. In other words, a natural death that couldn't be helped.

Nonetheless, Haibara knew she was very close to finding the antidote. All she had to do was to extract the green powder to make the substance that she needed for the antidote and then discard the rest of the drug in a way that no one could find or use for unspeakable purposes. And to play it safe, she wouldn't say anything about this creation, not even to Conan.

The chemist bit her lips, unlocked a drawer, and pulled out a small, rectangular container. There were two and a half pills of APTX-4869 in it; the missing half piece had been used in recent chemical tests. After placing the red-and-white capsule into the container, Haibara reached for a marker. Just in case someone found this container and thought the pills were medicine or candy. But Haibara never thought that once she labeled the capsule, the name would become official. With a name, there came the need for people to use it.

Haibara wrote down the first word that came to her mind, and in truth, she didn't know why she used that name to identify the capsule filled with the green powder.