Incoming traveller.
Ah, Jesus!
- Welcome back, SG-1. - Thank you, sir. It's good to be back.
- You're overdue. - Bit of a wild-goose chase, sir.
The remnants of a temple we discovered led me to believe we'd found Kheb.
The planet Sha're told me about.
However, there was no sign of Amaunet's Harsesis child.
Just rain.
Much rain. Wind, lightning, hail.
Did I mention the rain, sir?
Report to the infirmary.
I think we'd all like to change first. I have mushrooms growing out of...
Attention all levels. Stand by for contaminated materials transfer.
Infirmary. Yes, sir.
- Infirmary? - What?
I'm escorting you as a safety precaution. There's a big chemical spill on level 23.
- What kind of chemical? - Tetrachloroethylene ruptured.
- Ruptured? - The entire level's been sealed off.
Hazmat team's cleaning it up now.
- What? - There's no danger, sir.
Thank you.
Loosen your belt, please, Colonel.
How's a needle in my butt gonna get water out of my ears?
It isn't. Come on, sir. You know this is standard procedure.
We should rethink this procedure.
So, Daniel, in our galactic meanderings,...
...if we happen to stumble across this Narcissus child...
- Harsesis. - We're still talking about a baby, right?
- What? - What?
Attention. Contaminated material transfer in progress.
Please remain at your post until notified.
Listen, really jam it in this time, OK?
If Sha're's child is born with all of the knowledge of the Goa'uld,...
...it should be able to communicate at a much younger age, right?
Colonel?
- Daniel? - Just relax.
Let's begin.
It has something to do with the alien symbiote.
It took an extremely large dose just to sedate him in the first place.
- What is the problem with the human? - Her body chemistry has been altered.
It is related to her prior infestation by the dominant parasitical species here.
- Is there a way to compensate? - I have not found it yet.
Place them in a holding cell. Once the invasion is complete, study them further.
Only then will we know if this is a viable new home world. Come with me.
Take that one first.
Attention all levels. Contaminated material transfer in progress.
Remain at your post until notified.
Contaminated material transfer in progress.
- 23? - No, this one's going to 16.
Teal'c.
Major Carter, there is little time.
Are you capable of standing?
Oh. I feel sick.
You are suffering from the effects of a sedative.
What? What's going on?
- What the hell happened to them? - They are not who they appear to be.
There's been an alien incursion within the SGC.
A what?
Dr. Fraiser and General Hammond spoke of a procedure...
...which had failed to work upon both of us. They spoke of invasion.
Wha...? How does that add up to aliens?
I saw two of them in their natural form. Truly, they are alien.
What about the Colonel and Daniel? We have to know what's happened to them.
Come in.
- It's locked. - It's not locked.
- What about this chemical spill? - I believe it to be a subterfuge.
Not one camera's operating on level 23.
- Incoming traveller. - Try punching up the gate room.
There.
The O'Neill and Daniel Jackson we know would not welcome aliens so blithely.
Imposters?
How do we know we're the only ones not replaced?
There's no way of knowing, but if Hammond has been compromised...
Then we can't trust anyone in the mountain.
Alert General Hammond.
The base was designed to keep people out, not in.
If we can make it to the south gate...
- Our escape has been detected. - We won't make it out this way now.
I will purchase time for you to depart this mountain.
Keep 'em busy as long as you can. I'll come back.
Of that I'm certain.
Airport shuttles are located in the blue zone, hotel shuttles in the green zone.
Maybourne.
This is Major Samantha Carter. We have a foothold situation.
Major Carter? Where are you?
I can't tell you that, sir.
There's an outdoor café outside NID headquarters.
- In DC? - Four o'clock.
Uh...
- I'm gonna need a little more than that. - I repeat, we have a foothold situation.
You're outside your appropriate chain of command.
I have reason to believe that may be compromised, sir.
Understood.
Hey, Teal'c, how are you feeling?
You, uh... went a little crazy on us, so we had to sedate you.
- You remember what happened? - I do not.
SG-1 was exposed to chemical fumes from the spill.
You became delusional and attacked several people trying to escape.
Teal'c... glad you're awake. Has Dr. Fraiser explained the situation?
She has.
Good. We're hoping you can tell us where Major Carter is.
She also had an adverse reaction to the chemical.
One of the side effects is hallucinations, paranoia.
Your symbiote protects you from a lot, but apparently not tetrachloroethylene.
Where is she?
I do not know.
Teal'c, if she doesn't receive medical attention soon, she's going to get worse.
I won't lie to you - she could die.
- Hi. Can I get you some coffee? - Please.
Thank you.
So, you came to the one person you don't trust.
I don't know how far up the infiltration goes.
It may be contained within the SGC, but if General Hammond was compromised...
He sounded fine to me on the phone.
- What? - He called me, Major.
- Calm down. He's concerned for you. - I told you we had a foothold situation.
Major, a chemical spill causing paranoid delusion is more plausible to me...
- ...than aliens taking over the SGC. - My God.
You don't think I can tell the difference between the two?
- What was I thinking? - Oh, hi, Carter.
Maybourne, you are an idiot every day of the week!
Why couldn't you have just taken one day off?!
That's insubordination, Major.
For crying out loud, Maybourne, cut her some slack.
- She's not exactly herself. - And neither were we.
Sam, believe me, I know what you're feeling. It's the chemical.
I don't believe it.
All right. Exactly what are the side effects of this tetrachloro...
...ethyl mermaline stuff?
Hallucination, delusion.
- Paranoid delusion, I think, but go on. - Look, I know what I saw.
We were affected by the fumes the moment we got in the elevator.
Didn't even realise it was happening.
I vaguely remember having some water in my ear, that's it.
- Dr. Fraiser injected me with something. - She was trying to sedate you.
She didn't give enough to Teal'c. He sprung you and off you went.
He's fine, by the way.
Beat the crap out of a couple of SFs, but he's fine.
We're telling you the truth, Sam.
You should have followed procedure.
I fully intend to return with you just to make sure everything's all right.
And you agreed to that? Shouldn't that tell you something?
I wouldn't tell them where we were until they agreed to my inspection.
- You have no idea what you're going into. - I can take care of myself, Major.
If I don't report back in a few hours, you can rest assured that action will be taken.
We just want you to come back so Fraiser can check you out.
- You're asking? - We're asking.
So, I have a choice. I can walk away now?
- Yes. - No!
- Maybourne. - You will accompany us back to the base.
- If you resist, you will be handcuffed. - No, she won't.
This is very touching, but this conversation in this public place...
...is evidence that Major Carter is something of a security risk.
What's the matter with you?
It's starting to wear off, isn't it?
You're starting to think straight. That's exactly what happened to me.
I'm so tired.
We're gonna go now.
I'd like you to come with... but it's up to you.
All right.
Sure?
Good. Plane's waiting.
After you, Major.
Maybe you'll remember something later, son.
Please release me from these restraints.
I'm sorry, Teal'c. There's still a chance you could relapse.
Three of the men you attacked have concussions.
Yes?
You're certain she's been located?
Very well.
Then we may begin experimenting immediately.
Your tax dollars at work. Cosy jet you got here, Maybourne.
You've alerted General Hammond to expect me?
Oh, yes. He's awaiting your thoughts.
- So how exactly is Teal'c? - Oh, well, you know Teal'c.
Is the chemical spill completely cleaned up?
As of this morning the Hazmat team had gotten the last of it.
But they're gonna keep level 23 sealed off until they can figure out what happened.
Carter? What are you doing?
Don't move.
- Put the gun down. - She's hallucinating again.
What the hell is that?
Sit down.
Look out!
- Go check the pilot. He's one of mine. - You first.
Good enough? I'll keep an eye on him. Go!
General?
- What is that? - I don't know.
- What is that damn thing? - I told you I didn't know that Jack was...
Tell us how that thing works.
Sam.
Hold on a second.
So, this is how they look like us.
Where's the real Daniel? Is he still alive?
You can talk to us now, or to my colleagues later.
Either way, we'll find out the information we need.
Sit down!
It works.
It only creates an image. I couldn't hear Daniel's thoughts or anything.
- That must be what this one does. - Put that thing down, Major.
- What caused their images to blink out? - They were just sitting there.
Something interrupted both signals at the same time. We should figure out what.
We were levelling off. Uh, cabin pressure.
This is electronic. It was more like interference.
Noise from the engines, maybe. If we can replicate the conditions, we can find it.
All right.
Sorry, sir.
What the...?
Who's that?
Major Davis.
Colonel O'Neill.
What's going on? How did we get like this?
You're asking me?
Hook him up.
Report.
I thought the sedative might be interfering.
The symbiote is quite resilient.
- So is he. - Put him back in the holding cell.
Major Carter's on her way back. She may be less resistant.
Davis...
The latch for that thing is...
- You found it. - Yes, sir.
If there's another Fraiser, my guess is there's another you and me too.
Why are we the only ones awake?
Maybe, uh, maybe a malfunction.
- Colonel, what are you doing? - I'm gonna wake her up.
- Do you think that's such a good idea? - Well, it's an idea.
Maybe they didn't hear that.
Excuse me.
That was weird.
A nice alien like you's gotta carry a...
- Hello. - What about the other thing?
The other thing.
OK...
She's just an alien.
Just an alien.
Whoa, whoa.
Yeah, that's an alien all right.
Why don't you find something to tie it up?
Hello?
Colonel?
Yes?
It's you?
Yes.
It's good to see you.
Oh, my God. I figured they were keeping you alive in order to access your mind.
Whoa! Hey.
- Who are you? - Sir?
Oh, sorry.
Major Carter.
Oh.
Well, in that case, it's good to see you, too.
Every one of the people in this room has been duplicated by the aliens, sir.
Uh, noticed that.
The procedure didn't work on me or Teal'c.
We escaped, but Teal'c's been captured.
- Where's he? - I haven't had time to find him, sir.
- Maybourne's forces are moving in soon. - Maybourne? How'd he get...?
- I called him. - Willingly?
In 29 minutes those forces are gonna break down the front door...
...and shoot anything that resists. We need to get our people.
Yeah. I pulled that headband thing off of Fraiser. Her evil twin came running.
- Well, how did you two get free? - We just woke up.
That must have happened when I killed you.
I'm sorry?
I killed the aliens impersonating both of you.
- And they don't know you did this? - I don't know, sir.
There's a specific tone that will disrupt these devices.
- The machine's in my lab. - Go.
- Sir, we're gonna need more weapons. - Armoury.
Head on back to 23. Keep an eye on our people.
Yes, sir.
I've come for the bald prisoner.
You will come with me.
I will submit to no further experiments.
Oh, but you will.
- I'll take it from here. - I can't allow that, sir.
Oh, but you can.
Colonel O'Neill, I presume.
What gave it away?
That's it.
General Hammond.
General Hammond to the control room.
- Sure you're up to this? - As always.
You're an animal.
- What the hell was that? - Colonel! On your six.
- What's going on? - I don't know. They just ran.
- Perhaps there's an evacuation. - We can't let that happen, sir.
- Why not? - They've accessed our minds.
They know everything about us.
- Everything? - Everything.
Close that iris.
I can't, sir. It's overridden. I'm shutting down the gate.
Everyone, freeze!
- What happened? - They self-destructed.
Their destruction appears to be complete.
That's a lot of damage.
Coat of paint... little touch-up...
It'll be fine.
I've ordered P3X-118 locked out of our dialling program.
The human counterparts of those aliens woke up spontaneously.
We're assuming the signal stopped when they left.
Those who escaped still have knowledge obtained from being linked to your minds.
That's creepy.
We've changed all our codes. That's all we can do.
How did this happen? The aliens came through the gate impersonating SG-6?
We rushed them to the infirmary. We don't remember anything after that.
Hammond asked me to come, but wouldn't say why.
Presumably their next step after the SGC was the Pentagon.
A high-frequency blast every time a team returns...
...should prevent it from ever happening again.
Colonel Maybourne.
Good save.
I thought you'd like to know the alien posing as Dr. Jackson expired.
What of the aliens not caught in the explosion?
We're guessing they were linked to their leader when he self-destructed.
What about the aliens that escaped?
We'll never know. We'll have to hope the same thing happened to them.
We appreciate your help on this matter, Colonel Maybourne.
Credit Major Carter. I do.
Well, I'm, uh... sure we'll see each other again.
That'd be nice, Harry.