SEVEN

"Okay, what are you babbling about?" Piper asked when they had all gone back into her room.

"Alister," said Paige, "you used to be a doctor, right?"

"Well, technically I still am," said Alister. "But yes I was a doctor before I was a Whitelighter."

"Okay," said Paige, "tell me something. When someone gets a disease and the doctor uses a drug to cure it, what happens in the persons' body?"

"I'm not sure I understand what you're asking," said Alister.

"Let me see if I can explain this in a different way," said Paige. "Let's say that someone gets a disease. The doctor uses whatever drugs are needed to cure the disease and cures the person. What physiological changes occur in the body?"

"Well," said Alister, "the medications used helps stimulate the body's natural defenses helping to produce antibodies to fight the disease. In addition a lot of the medications can also attack the disease directly. Why do you ask?"

"But people can sometimes catch the same disease more than once, right?" Paige asked.

"Of course," said Alister. "Sexually transmitted diseases are perfect examples. No matter how many times a person is cured of them they can still be reinfected."

"So far so good," said Paige.

"Paige, what are you asking all these questions for?" Leo asked.

"Hang on a second," said Paige. "I'm almost finished. So, Alister, if a person is cured of a disease, can the disease still be in the person's system without causing them any harm?"

"Sometimes," said Alister. "Well, not exactly the disease. There are called genetic markers with most organic systems. Even if a person is cured of a disease they quite often retain the genetic markers of those diseases. It's one of the ways a doctor can analyze a blood sample and determine that a patient has had certain diseases."

"Great," said Paige. "And it's a well known fact that a disease can be passed from one person to another. Especially through such things as blood transfusions."

"What does this have to do Chris?" Piper asked.

"Leo," said Paige, "you need to get us another Whitelighter. One that's never been shot by a Dark Lighters' bolt. It's very important that whoever it is has never been shot by a Dark Lighter."

"What does that have to do with it?" Phoebe asked.

"Everything, I think," said Paige. "Okay, this is a bit complicated but just stay with me. When Chris was conceived Leo was infected with the Dark Lighters' poison. While Piper was carrying him he was protected from the poison but after he was born he didn't have that protection any more."

"We know all that all ready," said Piper.

"Yes," said Paige. "Now, after Chris was born it probably took twenty four hours for the poison to begin affecting Chris. That's why he seemed to be perfectly healthy after he was born. Once they found the toxin they immediately began to treat Chris for it. Only they had never seen Dark Lighter poison before so they had no knowledge of how to treat it.

"Then, Leo used his healing power on Chris. Alister, you said when you use your power to heal Chris it heals the Dark Lighter poison but his body seems to be producing it. What if his body wasn't producing it? What if he was being reinfected with it?"

"How?" Leo asked. "There's been no Dark Lighter activity since Chris was born. How could he have been reinfected with the poison?"

"Through you," said Paige. "And through Alister. I can't explain how or why but I think these genetic markers Alister mentioned are reinfecting Chris. Chris would have had the markers because he had the poison in his system. Leo's been infected with Dark Lighter poison more than once. And you told me that a Dark Lighter shot Alister when he came to help Leo after his accident.

"I think that the genetic markers from Chris' body and those in Leo and Alister's body are somehow combining and reinfecting Chris. Well all know that a newborn's immune system is very fragile. They don't have the immunities we have because they haven't been exposed to the same diseases we've been exposed to. Which, I presume, helps strengthen the immune system."

"Yes, it does," said Alister thoughtfully. "And although I've never heard of anything like this happening I believe it might just be possible. If Chris were fully human it wouldn't affect him. But he's half Whitelighter. Paige, you may just have something here.

"Leo, got back up there and bring down a Whitelighter named Carl Rettick. He's been a Whitelighter for about twelve years but I know for a fact that he's never been infected by a Dark Lighter's bolt. He spends most of his time with the Elders."

"I'll have him down here before you know it," said Leo, turning to leave the room.

"What made you think of this?" Alister asked.

"It's what you said about sterilizing the instruments at the morgue," said Paige. "When I was heading home I was thinking about that. And it occurred to me that Chris' system was contaminated with the Dark Lighter poison."

"You're a very smart young lady," said Alister.

"Thanks," said Paige. "I just hope I was able to be of some help."

"We'll know when Leo gets back," said Alister. "It shouldn't be more than a few minutes I would imagine."