According to the Atlantis xenomicrology department, the Pegasus Galaxy natives were just far enough off from baseline Earth human that they weren't susceptible to the same microbes -- and vice versa. This came as a huge relief to Elizabeth, because it meant that they didn't have to worry about wiping out half the galactic population with a common cold. Or, for that matter, having the same thing happen to them.

However, like most of the blanket pronouncements of the scientific establishment, this had turned out to be not entirely true. Over the years they'd encountered a small handful of bugs that went both ways across the biological divide.

They found another one, about eight hours after leaving Sateda, when McKay, Sheppard, Beckett and Teyla were all admitted to the sickbay within half an hour of each other with the same symptoms: vomiting, blurred vision, a skyrocketing fever and the very disquieting ability to hear each other's thoughts.

"Satedan psychic fever," Ronon reported, leaning a hip rather stiffly on the edge of Sheppard's bed. While he was technically supposed to still be in bed, the Daedalus medical staff had obviously realized that it was wiser to let him come and go as he pleased.

Despite the greenish pallor to his skin, Rodney's glare would have melted lead. "There's no such thing. That's scientifically impossible."

Ronon just looked amused, the first time he'd really smiled since leaving his homeworld. "So how do you explain it, then?"

Rodney spluttered. From the other side of the all-too-small sickbay, there was a sudden smack as Teyla hit Sheppard with a pillow.

"What was that for?"

"You were thinking about my breasts." Teyla moaned and hunched down in her bed. "I do not care for it. Kindly stop it."

"I wasn't trying to!"

Beckett rolled over long enough to say, "Teyla love, the average Earth male thinks about sex every seven seconds, I'm sorry to tell you." Giving Sheppard a dirty look, he added, "More frequently, apparently, in some cases."

Teyla made a small whimpering sound and pulled her blanket over her head.

"Should you be in here?" the Daedalus doctor asked Ronon.

"I've had my shots. Back when I was a kid. I can't get it."

Rodney groaned and rolled over, then winced as he was reminded of his other, still-healing injury. "I cannot believe this is the thanks I get for saving your ungrateful ass." His head popped up and he stared balefully at Carson. "What do you mean, I'm an egotistical bastard and it wasn't me who saved him?"

"I didn't say anything!"

"You were thinking it! And you, for God's sake --" His glower rolled over to Sheppard. "Can't you go for a few minutes without -- oh my God, that's disgusting! And anatomically impossible! Stop thinking about that!"

"I'm not doing it on purpose, Rodney; it just happens!"

Things got exponentially worse over the next couple of hours, as nearly every crew member on the Daedalus came down with it. The only one who didn't seem susceptible was Hermiod.

"Is this thing fatal, Ronon?" Beckett demanded the next time the Satedan turned up in the sickbay. With shaking hands, the doctor was trying to change Sheppard's IV.

"Never," Ronon said, adding after a moment, "Not for Satedans, anyway." After watching the doctor fumble with the bag of saline solution, he reached out one long arm and hooked the bag on the IV pole. Carson nodded thanks and accepted Ronon's supportive shoulder on the way back to bed.

"Oh thanks, that's comforting," Rodney snapped.

"Doesn't last very long, either. You should be over it in a day or so."

Caldwell lurched into the sickbay, heading straight for the medical supply cabinets. He grabbed a bottle of painkillers, swept a withering glare across all of them and then staggered out.

"Yeah, we hate you too!" Rodney yelled after him, and went into a coughing fit.

Ronon offered him a cup of water.

Sheppard peeled himself away from his pillow long enough to ask, "I don't know if I really want to know the answer to this, but who's flying the ship?"

Ronon supported Rodney with a hand under his back while he drank. "That little gray guy, and me."

"I was really afraid you were going to say that."

Ronon glanced over the rest of them. "Anybody need somethin' while I'm here?"

"Water would be very nice, please," Teyla said.

He got her a cup of water, and a wet towel for one of the other patients -- the overwhelmed medical staff had eventually given up on trying to fit everyone in the sickbay and just confined people to quarters, but it was still filled nearly to overflowing. After he left, the four remaining Atlanteans looked at each other.

"Yeah," Rodney said. "I agree."

"And this isn't life-threatening at all?" Elizabeth asked over the radio, apparently unaware of the irony of her statement, as Teyla left to go stop Ronon and Hermiod from killing each other.

"Apparently not," Carson and the Daedalus doctor answered simultaneously, then glanced at each other. She made an "after you" gesture. "The symptoms seem to be fairly straightforward and resolve without treatment in a day or two. It's highly contagious, though. If we all caught it, then it must stay in the environment for decades."

"Well, since the Daedalus has its own self-contained life support system, we're going to use it for an isolation chamber until everyone's over this. Then we disinfect the hell out of it."

"Wait just a minute here," Rodney piped up. "You're going to leave us in here? Trapped? With each other?"

"That's what 'isolation chamber' tends to imply, Rodney."

"Shut up, Carson, I wasn't asking you. And you shut up too!" He stabbed a finger in Sheppard's direction.

"I didn't say anything."

"I hate all of you people."

Elizabeth cleared her throat. "Right now we're prepping a team from the Atlantis infirmary to beam up in contamination suits."

"I'd also like to get some samples and see if we can't manufacture our own vaccine," Carson said.

"Good thinking. I'll pass that along. Oh, and John?"

Sheppard tried to look alert. "Mmm?"

"When I asked Ronon for an incident report, he just laughed. Could you talk to him for me, please?"

"Elizabeth, I thought we agreed we don't make Ronon write reports, and you and I both remember why."

Elizabeth shuddered. "I know that, but he's the only one of you who's been fully coherent for the last twenty-four hours."

"We're all psychic right now. I can just read his mind and write a report about that."

Rodney barked a laugh. "I can't wait to read that."

"I can't wait to read all of your reports," Elizabeth said dryly, "considering that from all accounts, you've just spent quite a few hours in close proximity to one another while undergoing a sort of -- uh --"

"Pegasus Galaxy Vulcan mind-meld," Sheppard supplied promptly, smirking at Rodney's dirty look.

"Yes, enduring his disgusting fantasies."

"There's nothing disgusting about my fantasies." The smirk widened. "You, on the other hand, I have to wonder about -- especially that one involving Carter, polynomials and a tub of chocolate frosting --"

Rodney made a furious squeaking sound.

"Oh, look at the time," Elizabeth said hastily. "From the sound of things, you're all feeling better, so check back in six hours or so and we'll see if we can get you decontaminated and back to Atlantis, why don't we? Weir out."

There was a brief silence in the wake of Elizabeth's voice. Ronon walked into the sickbay in the middle of this. He stopped and looked at them. "You people okay?"

Rodney rolled over onto his back and put his arm over his eyes. "Ronon, do me a favor and go kill Sheppard for me, wouldya?"

"Too tired." Ronon flopped down on the nearest unoccupied bed -- one recently vacated by a Daedalus crew member who was feeling well enough to go back to her quarters -- and closed his eyes.

Carson pushed himself up to his elbows, his inner doctor overcoming his physical infirmity. "When was the last time you slept?"

"Got sedated when you people took the tracker out of me," Ronon mumbled. "Thanks, by the way."

"Are you telling me you haven't slept since then?" Carson was sitting up fully now. "Have you been checking the sutures in your leg? And taking the antibiotics I gave you?"

After a pause, Ronon's sleepy mumble: "I know how to take care of myself, Doc. Been doing it for seven years."

"I think what he's trying to say," Sheppard drawled lazily from his own bed, "is that we're all worried you've been too busy taking care of us to take care of you."

"Speak for yourself," Rodney said sharply. "He's speaking for himself, there."

"Rodney, we can all read your mind."

"Shut up."

"Still reading your mind."

"Read this, then."

"Wow, McKay. And you were telling me about anatomical impossibility earlier?"