A/N – This is a rewrite. I wrote and posted the original first chapter, then thought up a better way of starting this…Anyway, hope you enjoy, and reviews are always appreciated. Oh, and please feel free to correct me if I got any of the medical facts wrong, I'm not claiming to be an expert…

Elysium – In Greek mythology, the part of the underworld where the spirits of the heroic and virtuous reside.

Xibalba – "Place of Fear" In Mayan mythology, the underworld which is ruled by spirits of disease and death.

Chapter 1: Diagnosis

"No no, my point is the SETI people would probably just try to make friends with the goa'uld and end up getting blown up," Jack said loudly.

"Jack," Daniel rolled his eyes. "I think they'd be intelligent enough to realize the goa'uld are hostile."

Sam and Teal'c exchanged a look. Sam shook her head and took another sip of beer, letting her gaze wander around the rest of the crowded bar. It was late on a Friday night and the team had just gotten back from a particularly long and boring mission to a swamp planet that had left them all smelling like sewage and desperate to do something fun.

"Well, whatever, I still don't think the program should just suddenly go public." Jack muttered into his glass.

They lapsed into companionable silence then, until Daniel glanced over and saw Sam rubbing the bridge of her nose with a pained expression. "Hey, you ok?"

"What? Yeah," Sam smiled. "Just a headache."

"This place can do that to ya," Jack glanced at his watch. "It's getting pretty late, though, maybe we should head back home."

They all stood up and grabbed their coats from the backs of their chairs, sorting out who was paying for what before heading towards the door.

"Teal'c and I are heading back to the base tonight," Daniel said as they walked out into the parkinglot.

Jack gave him a look. "Why? Don't you wanna go home, put your feet up and watch the hockey game?"

"Uh, no. I'd much rather get back to translating those Phoenician tablets they found on P9X-256." Daniel replied, pulling his keys out of his pocket.

"Whatever floats your boat. Carter, you need a ride home? Or are you gonna go back to the base too?"

"No, a ride would be nice." They waved goodbye to Daniel and Teal'c, then Sam followed Jack over to his truck. As she climbed into the passenger seat Sam was reminded exactly why she preferred small cars and motorcycles…Her head throbbed again and Sam closed her eyes.

"You sure you're alright?" Jack asked, sounding concerned.

Sam waved her hand dismissively as he started the car. "I'm fine, sir, really. I'll just take some Tylenol when I get home."

"Okay…" Jack pulled out of the parking lot and started off in the direction of Sam's house.

They rode in silence, Sam with her eyes closed and a slightly uncomfortable expression on her face. Jack was frowning thoughtfully at the road, thinking about nothing of real importance except that night's hokey game. Suddenly, out of the corner of his eye he saw Sam slump forward, her whole form going limp.

"Carter?!" Jack cut the steering wheel sharply to the right, pulling the car up along side the car and turning to face Sam, shaking her shoulder. Seconds later Sam's eyes opened slowly and she squinted at him.

"Nynnn…sir…what happened?"

"Dunno…" Jack's eyes were wide as he pulled his gloves off to feel Sam's forehead. "You just passed out for a minute there. How's the head?"

"Still hurts." Sam bit her lip. "I feel really weird."

"Ok." Jack reached across her to the glove compartment, opening it to take out his cell phone. "I'm gonna call Fraiser and tell her I'm bringing you in. You think she's still at the base?"

Sam squinted at the clock on the dashboard and shook her head. "No. She's probably on her way home."

Jack nodded and dialed Janet's number, keeping a close eye on Sam as he did so. She seemed more worried than pained now and leaned to the side against the door, still chewing her lip.

"Ok, so what happened now?" It was fifteen minutes later and Sam was sitting on one of the infirmary beds while Janet checked her over. Jack stood nearby, arms folded over his chest.

"We were driving home and Carter just went all limp and lost consciousness."

"Sam?" Janet looked back at her friend. "Have you been experiencing any other symptoms? Headaches? Nausea? Disorientation?"

"Headaches."

"When did they start?"

"Earlier today. Before we came back." Sam thought a moment. "And right before I passed out I was feeling kinda strange."

Janet frowned. "Strange? You mean like dizzy, lightheaded or something else?"

"Not dizzy…I can't describe it, really."

"Okay…" Janet flipped to a new page on her clipboard and jotted something down. "I'm just going to run a few tests, see if we can figure out what happened here."

"You don't think I just fainted?"

"I don't know." Janet patted her shoulder reassuringly. "Lets just run these tests and see what we come up with."

Jack looked down at Sam as she sat back in the bed. "While Doc does that I'm going to go find Danny and T, ok? I'll be back in a little bit." Sam nodded, not looking at him.

Jack found Daniel in his office and Teal'c in the exercise room. They both seemed concerned, but Jack told them he'd relay the results from the tests as soon as Janet had them. Finally he headed up to Hammond's office, where the general was just getting ready to head home for the night.

"Is Major Carter going to be alright?" Hammond asked, concerned as Jack walked with him to the elevators.

"No idea, sir," Jack said. "Between you and me Fraiser seemed a little worried, which obviously isn't a good sign."

Hammond scowled. "Well, call me when we know what's wrong."

"Yes sir." Jack stood for a moment, staring at the elevator doors long after they'd closed behind Hammond, before punching the down button to head back to the infirmary.

Janet was in her office when Jack got back downstairs and she beckoned him in. "We got the test results back."

"And?" Jack sat down, noting with worry the slight furrowing of the doctor's brow.

"And…they indicated that she suffered a mild seizure back there." Janet shuffled some papers around. "We're getting ready to run an MRI and CT scan to try and figure out the cause. But as of now I don't know what it is."

Jack narrowed his eyes. "Doc, you're worried about something."

"Well of course I'm worried," Janet said. "But Sam's been complaining about headaches more often than normal lately and she's also been loosing weight. Not dangerously but enough to notice."

Jack scowled and leaned backwards so he could see out into the infirmary where a nurse was prepping Sam for the scans. "What do you think it means?"

"That's what we're running the tests for, colonel." Janet replied. "Seeing as no one else has shown similar symptoms I'm going to assume that this isn't something that happened to her off world. However, I'm not ruling out the possibility."

"Hammond wants to know when you figure it out."

Janet nodded. "I'll give him a call." She got to her feet, and Jack followed suit. "This is going to take a while, colonel, so if you want to head home…"

"Nah, I think I'll stay here. I'll just be in Danny's office or my quarters."

"Alright, I'll let you know when we find anything."

"Great." They walked back out into the infirmary, and Jack briefly made eye contact with Sam, noting the worry in her eyes and giving her what he sincerely hoped was a reassuring smile.

"Primary central nervous system lymphoma. It manifests through deep tumors in the brain and usually occurs in patients with diseases like AIDS," Janet explained to the group before her. "But recently the population of immunocompetent patients - those without aids - has been increasing."

"The type of lymphoma I had was similar to that," Jacob Carter said from where he sat to his daughter's right. "I didn't think it was genetic."

"It isn't," Janet said. "But your family very well could have some genetic condition that makes you predisposed to developing it."

"And you're sure that's what Major Carter has?" Hammond asked, folding his hands and frowning.

Janet nodded sadly. "Positive, sir. It's what all the tests indicated and the symptoms she's been showing are some of the common ones of PCNSL."

"So what's the cure?" Sam asked. She'd been staring down at the table the whole time, shoulders hunched slightly.

"As of now…" Janet said quietly, her voice almost shaking. "There isn't one. There are treatment plans that can extend survival to four years if we're lucky…radiation and IV methotrexate…But other than that there aren't many options, I'm sad to say…"

"Tok'ra symbiote?" Jack said, but Jacob shook his head.

"There aren't any free." He shot his daughter a sad look. "I would gladly give her Selmak but he doubts that even if he was young he'd be able to do anything for her."

Jack glared at Jacob. "Healing device? Sarcophagus?" Jacob shook his head again. Jack slammed his fists down on the table. "Damnit there's got to be something we can do!"

"Colonel, calm down." Hammond said forcefully.

"Excuse me for getting a little worked up about this, general! But she's too important to lose!"

Sam looked up at him. "Sir, please…don't…"

Jack sighed and sat down, slowly. "I'm sorry, Carter."

"I will talk to the other tok'ra," Selmak rumbled. "I can see if they know of anything that could help Samantha."

"Thank you," Janet said, giving him a weak smile. "Right now, however I think the best thing is for us all to get some rest. It's been a long night."

They all nodded in agreement and stood, slowly filtering out of the room. Janet remained behind with Sam and Jacob.

"I'm so sorry, Sam…" she said, walking over and pulling her friend into an embrace.

"It's not your fault," Sam murmured.

Janet sighed, stepping back. "I know but…" she shook her head. "If there's anything I can do."

"Some pain killers might be nice. My head still hurts."

"Ok. Just come down to the infirmary with me." Janet turned to Jacob. "Are you staying on base for a while or heading back?"

Jacob glanced at his daughter. "I might as well stay for a bit."

"Good." Sam whispered, walking over to hug her father.

Each member of SG-1 retreated to their corner of the base to digest the information. Daniel found himself pulling books at random off the shelves of his office, as if in the vain hope that one might contain an answer. He knew he was tired, but also knew that he wouldn't be able to sleep, so for the rest of the early morning hours he just kept filling and refilling his coffee cup.

He was sitting at the table, staring down at the Phoenician tablets he'd been translating when there was a light knock on the door. "Oh…Jacob. Hi come in."

Jacob walked over. "Selmak wanted to talk to you about something…it's got to do with Sam."

"Oh?"

"I am sure, Dr. Jackson," Selmak said. "That you've heard of the tree of life or the world tree?"

"Yes…different myths from all around the world contain references to something like that…ancient mayans, Egyptians, even the Bible…"

"It will come with little surprise to you, then that such a thing exists."

Daniel scooted to the edge of his chair, eyes widening. "Really?"

Selmak nodded. "Yes. Though no one in the history of this galaxy has been able to reach the tree. According to the Tok'ra lore and what we know from the writings of the Ancients it is located at the center of the universe and supposedly the origin of everything in existence."

"The center of the universe?" Daniel raised his eyebrows skeptically. "Has anyone actually ever been there?"

"Ancients, yes." Selmak said. "They supposedly left behind instructions for finding the tree. A legendary journey that most fail on." He looked at Daniel pointedly. "Many, I'm sure, would not believe that mere humans could ever make the journey. But I have faith in you."

Daniel stared at the tok'ra, disbelieving for a few moments. "You really think that's what we could do to save Sam? Go chasing to the center of the universe?"

"What other options are there?" Selmak said. "Short of letting her become a goa'uld and praying that that somehow saves her?"

"I was thinking…if we could get our hands on a sarcophagus…"

"Dr. Jackson." Selmak shook his head slowly, as though he were putting up with a child. "Do you realize how many times she would have to use the sarcophagus to be healed properly? The damage that would cause alone would probably be equal to that which the disease is causing."

"Yeah, but the tree of life…?" Daniel made a helpless gesture with his hands.

Selmak sighed. "Have you heard of the planet Dakara?"

"I think so…that's where the Jaffa were first implanted with their symbiotes, right?"

"Yes. It's sacred to both goa'uld and Jaffa, and heavily guarded. However, it is also the location from which the Ancients seeded all life in this galaxy. There is a library there, with books that detail the journey necessary to reach the tree."

"And you think we should go check it out?"

"Yes." Selmak nodded. He closed his eyes, dipping his head slightly. When he raised it again, it was Jacob who spoke.

"Daniel, he wouldn't have suggested it if there wasn't chance of it working."

"Yeah, I just think the others are going to have a hard time buying this." Daniel said.

Jacob nodded in agreement. "I know. That's why we wanted to tell you first. But, Daniel, it's not as far fetched as it might seem. And you of all people should know that you guys are capable of conquering all odds."

"Yeah." Daniel took off his glasses and closed his eyes, pinching the bridge of his nose between thumb and forefinger. "I want to save her. Jack was right, we can't lose her."

"I know. She's my daughter."

Replacing his glasses, Daniel looked up at Jacob. "I'll go talk to them. At least we could go check out the books on Dakara. Maybe they'll have some answers."

"It's always a start."