Season 1, Episode 20: There but for the Grace of God

The SG-1 team walked through the Stargate onto the alien planet dubbed P3R-233.

"Well, this place is definitely alien," Colonel Jack O'Neil said, his long Special Forces career making him look more for threats than for the cultural or technological marvels that his teammates would be looking for. "Sam, Daniel, why don't we split up for no good reason? You guys can check over there, Teal'c and I will check over here."

"With respect sir, the very sensibly pre-planned Stargate Exploration Protocols specify that the team should stay together," Sam said politely. She carefully did not roll her eyes.

"Right. Thank you, captain," Jack said, voice heavy with snark. "Lead on, then."

Before Sam could choose a direction, Teal'c spoke. "Colonel O'Neil, we need to leave this place immediately."

Jack glanced once at the strange monster-shaped piece of ironwork that Teal'c was staring at, then turned for the Stargate. "Right, let's go. Daniel, dial us home."

Moments later, the team was back in Stargate Command on Earth. Jack waited until the wormhole was safely closed behind them, then turned to Teal'c. "Okay, what was that all about?" he demanded. "I trusted your judgement because you're a respected teammate and there was no reason not to do what you said and then ask questions once we were all safe. Now that we're safely back in SGC, I'm asking questions."

"That sign was a Goa'uld marker," Teal'c explained. "It means 'stay away.' It is placed on worlds where the Goa'uld have wiped out all life. The surface of that planet will be enormously radioactive."

"Oh," Jack said. "Good thing we left. Okay, everyone hit the showers. We'll debrief in half an hour."

A few weeks later the Goa'uld showed up in their spaceships and killed everyone.

Wait, that was depressing. Let's try a different Everett branch...

"That sign was a Goa'uld marker," Teal'c explained. "It means 'stay away.' It is placed on worlds where the Goa'uld have wiped out all life. The surface of that planet will be enormously radioactive."

Sam waited a beat, but Teal'c was finished talking. "The surface will be radioactive?" she asked. "The Geiger counter on the MALP wasn't going off, so I'm guessing that facility was well underground. It should be safe to go back."

"There's a Geiger counter on the MALP?" Jack said in surprise. "Since when?"

Sam looked at him in barely-concealed disgust. "Since always?" she said. "That's pretty much the point of the MALP robot that we send through the gate before we go to a new world for the first time; the MALP tells us if the area immediately around the gate is safe. The video cameras tell us that there are no giant pits for us to fall into or people with guns to shoot us, the thermometers tell us that we won't instantly burst into flames or turn into popsicles, the air monitor tell us we won't suffocate from lack of oxygen or have our lungs melt from gaseous sulfuric acid, and the Geiger counter tells us that we won't suddenly grow a second head."

"That was an excellent expository infodump about the MALP, Captain Carter," Teal'c said with an approving nod.

"Thanks, I practice," Sam said.

"Personally, I'm still trying to convince them to put a basic automated bio-lab on the MALPs," Daniel said. "It would be good to know if the place is crawling with some disease that will kill us all. At the very least we should be going through in hazmat suits until we're sure there isn't an airborne Neanderthal virus or something."

"That is an excellent point, Daniel Jackson," Teal'c said. "I will get the suits."

~twenty minutes later~

"Chevron seven, locked!" Walter said, redundantly as always. If the giant glowy light and movement of the seventh chevron hadn't made it clear that it was locked, the kawoosh as the gate opened would have been a pretty good clue. Still, announcing what everyone could plainly see made him feel like he was contributing, so no one said anything.

The hazmat-suited SG-1 went through the gate and started exploring the facility.

"Hey, guys, look at this," Daniel said. "Some kind of weird mirror thing. I wonder what it does?" The others watched in interest as their resident mad social scientist stepped closer and ran his hands over the surface of the mirror; a visible jolt of electricity passed over him and he vanished into thin air.

"Jack?" Daniel said, looking around the suddenly empty room. No response came back. "Sam? Teal'c? Come on guys, this isn't funny."

Operating under the very sensibly pre-planned Stargate Exploration Protocols, Daniel called the others on the radio and, when he got no response, did a fast sweep of the area. The others were nowhere to be found, so he immediately retreated to the gate. Notifying SGC would let him bring backup in to help with the search, and would prevent him from being just another missing person.

Unfortunately, the moment he walked through into SGC he found that missing comrades were no longer his biggest problem.

"Put your hands on your head!" the gate-room guards shouted, pointing guns at him. "Who are you?!"

"What?" Daniel said, putting his hands on his head. "I'm Daniel Jackson. Is this a joke?"

It wasn't a joke. Three minutes later he was in the briefing room under guard when Dr. Langford walked in.

"Catherine, what are you doing here?" Daniel demanded in surprise. "What's going on?"

"You know me?" Dr. Langford said in surprise.

"Yes!" Daniel shouted, his frustration getting away from him. "I'm Daniel Jackson! You brought me in to translate the cartouche in Egypt! I helped build the Stargate program! We're friends, have been for a long time!"

Catherine frowned. "I've never met you before," she said. "But, given that I've seen duplicate SG-1 members made by crystalline intelligences and SG-1's consciousnesses switched into robot bodies, I'm prepared to believe that something strange is happening. Sit down and let's figure it out."

With both parties working together like sane people it didn't take long.

"I'm in a parallel universe?!" Daniel demanded. "You mean a different Everett branch, so named for the Many-Worlds Interpretation of quantum mechanics as formulated by Hugh Everett in 1957 in which he stated that every decision, no matter how tiny, causes a variety of new realities to branch off, one for each possible outcome of the decision, thereby resulting in an infinite array of realities many of which are essentially identical but some of which might be radically different?"

"Yes, exactly," Catherine said. "Nice expository infodump about Everett branches, by the way."

"Thanks, I practice," Daniel said.

"What I'm interested in is that you mentioned knowing the coordinates for Chulak," General Jack O'Neil said. "Give them to me. If this Chulak is the home world of the Jaffa who are the soldiers of the Goa'uld aliens who are currently busy exterminating all life on Earth, then I want to send a nuclear bomb through and blow up all the Jaffa on Chulak before that Goa'uld ship that just killed the President gets here."

"Nice expository infodump about the major aliens of this franchise," Catherine said.

"Thanks, I practice," Jack said. "Now, Daniel—coordinates? I want to get the bomb rolling."

"Well, you could," Daniel said. "But wouldn't it be better to hold off on that? There aren't actually very many people living near the Chulak gate, and they're mostly just primitive non-combatant slaves. Most of them are family of the Jaffa who are invading us, so actually sending the bomb through will just piss off the invaders, but the threat of sending a bomb through would give you some negotiating leverage. Not a lot, though, since the guns on the Goa'uld spaceship are big enough to blow up the Stargate Command facility that we're all sitting in, even though SGC is buried under Cheyenne mountain."

"Nice expos—"

"Thank you, Catherine," Daniel said, waving her quiet.

"Good point, Daniel," Jack said. "Okay, well, we're still evacuating people to the beta site, so we'll focus on that instead of taking time out to send a bomb to kill a few people who aren't involved in the immediate invasion anyway; that way we'll save a lot more lives. And we can always bring a few bombs through to the beta site; there's a gate there, so we can still send one to Chulak later, once all of our people are safely evacuated."

"Good idea," Daniel said. "On that subject, I'd really like to go home. Can you send me back to planet 233? Like Catherine said, that mirror is probably what sent me here; maybe I can use it to get back."

"I'm sorry, Daniel, but we can't take the time out to open a wormhole to 233," Jack said. "We need to keep evacuating people to the beta site ASAP."

"Wait, a minute ago you were going to take time out of the evacuation to send a bomb that wouldn't have done much good," Daniel said. "Besides, if you open the gate to 233 your refugees can go there with me and then move on to the beta site from there after I'm gone. If I'm crazy then sending me to 233 doesn't cost you anything but a few minutes, and if I'm not crazy then you'd be letting me save a billion and a half people."

"Oh, good point," Jack said.

A quick trip to 233, through the mirror, and back to home-dimension SGC later...

"Wow, you guys will never guess what just happened," Daniel said. "Check out this video that I carefully made in the other Everett branch. It's full of statements from other versions of people we know in order to prove what happened, and it also contains all the information they had on the upcoming Goa'uld attack so we know what to prepare for, as well as full records of all the planets they have visited in case we haven't visited some of them."