Tarchannen III investigation, star date 40164.7.
Ensign Anthony Brevelle recording. Lt Susanna Leijten in command.
- You up and running, Brevelle? - Yes.
I checked buildings four and five. Just like the others.
No phaser hits, no sign of a fight, it's like the outpost just vanished.
You'd better come see this. No footprints, no vehicle tracks.
The wind probably erased them. But look...
That's Hickman on the right, Mendez on the left.
As noted, the recording was made by Ensign Brevelle five years ago.
You said before Brevelle deserted Star base 112 last week,
he'd been ill for several days. What about Mendez?
Mendez was seen on the Aries an hour before she disappeared.
According to witnesses, she seemed normal.
He just passed a routine physical on Alia IV with flying colours.
No, wait, I know Paul Hickman. He's a family man with two kids.
He wouldn't steal a shuttle and desert.
He was spotted by a supply ship yesterday,
on course to Tarchannen III.
The original disappearances were never solved?
No. We never learned what happened or why. 49 people, gone.
And five years later the away team investigating their disappearances
have started to disappear themselves.
Geordi and I are the only two left.
Space, the final frontier.
These are the voyages of the Starship Enterprise.
Its continuing mission, to explore strange new worlds,...
..to seek out new life and new civilizations,...
..to boldly go where no one has gone before.
Captain's log, star date 44664.5.
We have set a course to intercept Lt Hickman's stolen shuttlecraft,
and, hopefully, to discover the whereabouts of the missing officers.
And then, I almost married Paul Bogrow.
Bogrow? Bogrow, now, which one was he?
You remember. The one with the thin moustache.
- Not Bogrow! - I know.
The one who always used to drive you crazy?
You always thought he was so full of himself.
Well, I decided that I had prejudged him unfairly.
And then I decided that I'd been right in the first place.
What about you?
I enjoy the bachelor's life too much.
Doesn't sound like my little brother who always wanted advice on women.
Yeah, obviously you were a... a great advisor.
- What do you think? - I don't know.
But I'm not ashamed to tell you, I'm a little scared, you know?
Yeah,... I know.
If anyone can figure this out,
it'll be the Leijten and La Forge show.
- Yeah. - We always made a good team.
A hell of a team.
Cmdr La Forge, Cmdr Leijten, to the bridge.
We have a fix on the missing shuttle.
On our way, Commander.
- Entering the Tarchannen system. - Slow to impulse power. Mr. Worf?
Long-range sensors holding on the shuttle,
bearing 010 mark 271.
Hail the vessel.
Lt Hickman does not respond, sir.
Put a repeating message on all channels.
Order him to come about and stand to. Priority one.
- Still no response, sir. - The craft is now in visual range.
The shuttle is accelerating.
Its trajectory is moving directly into the planet's atmosphere.
He will reach an atmospheric interface at an altitude of 210 kms.
If he stays at that speed, he'll self-destruct.
- Correct, Commander. - How soon, Mr. Data?
- 53 seconds, sir. - Options?
He's out of transporter range.
He's too far away to get a lock with the tractor beam.
- Open a channel. - Open.
Lt Hickman, listen carefully.
This is Capt Picard of the Enterprise.
You are in danger. Slow your rate of approach.
The shuttle is approaching the outer thermosphere.
- He's panicking. - At current acceleration,
the shuttle will be destroyed in 28 seconds.
- 16 seconds to impact. - Lt Hickman, do what I tell you.
Reduce velocity, bring your craft to a positive pitch of 20 degrees. Now!
The shuttle is entering the lower ionosphere.
Sensors detect two more Federation shuttlecraft on the surface.
No life signs.
- Number One, prepare your away team. - Worf, Data, Geordi.
I'd like to volunteer to join you, sir.
Leijten, Geordi, check the shuttle.
Data, Worf, you've got the perimeter.
It's the shuttle pod Mendez stole from the Aries.
No life signs, Commander.
Sir, I am certain we are being watched.
Found it in the shuttle.
Where's Cmdr Leijten?
Riker to Susanna, report.
Fan out. Let's find her.
La Forge to Leijten.
Where have you been?
Mendez and Brevelle are alive.
- You saw the footprints? - Yeah.
- But they're not human. - They're here.
Just stand still and listen.
You can feel it. They're here.
I'm not picking up anything.
Wait a minute. Where are you going?
- Stay away! - Suz,...
La Forge to Enterprise, medical emergency. Two to sickbay!
- Do I look as bad as I feel? - You look fine... now.
- What happened? - Your blood chemistry is way off.
You had a histamine response. To what, I don't know.
I'm running a blood and tissue analysis.
I need to get back to the surface.
Until I have some answers, I don't want you to leave the Enterprise.
- I have work to do. - Look, Commander,
you may have just had an anxiety reaction down there,
but I've got to know for sure.
Might not be such a bad idea to take it easy.
I won't stay locked up on this ship while the investigation's going on.
Your devotion to duty is admirable,
but Dr Crusher is right, you'll remain on board
until we know if this is connected with the disappearances.
- Captain... - We've surveyed the surface.
Analyzing all that data will keep us busy for a while.
Yes, sir, I understand.
Data's got a preliminary report if you're up to it.
Sure. Let's get going.
- What about La Forge? - I gave him a complete bioscan.
The results say he's in perfect shape.
That's what the reports said about Mendez and Hickman
before they disappeared.
Capt Picard's wrong. The best way is to go back with a dozen away teams,
fan out from the shuttle, cover a lot of ground fast.
- Use proximity detectors, sensors... - Susanna.
It's started! What if what happened to the others is happening to me?
You don't know that.
Suz, I'm here
and I'm not gonna let anything happen to you, OK?
OK. Come on.
During examination of the torn uniform,
I discovered these alien skin cells.
- Source? - Undetermined.
Without something to compare, it'll take weeks to identify them.
Fortunately, we have more evidence.
that these footprints were not made by any known Tarchannen life form.
If we're pursuing a theory that somehow unknown aliens are involved,
I should tell you that we didn't find tracks like that
- during the original investigation. - The planet has frequent sandstorms.
Prints might have been obliterated prior to your arrival.
Dr Crusher and I will search the medical database
in an attempt to match these with some known life form.
Aliens or no aliens,
why would our people return after five years, to be abducted?
Some sort of compulsion, like a post-hypnotic command.
Something that happened while we were there before?
We can take the records and chart everyone's movements.
Look for some commonality, something we all touched.
Maybe... a plant, or... the sand.
Or even something we ingested. It could even be in the air itself.
The parameters are broad, Data.
Any match we make will be inconclusive at best.
I am aware of that. I see no other reasonable course of investigation
available to us. We may not have much time.
You're worried about Geordi, aren't you?
I am an android. It is not possible for me...
For you to feel anxiety.
Starfleet personnel have vanished. Others may be at risk.
We must try to find out why.
However, I am...
..strongly motivated to solve this mystery.
We're wasting our time.
That's not how you felt before.
It was your idea to look for a commonality.
Yeah, well, I was wrong.
We're not going to find anything this way.
We should go back to the planet.
It's all down there, everything we need to know.
That's just not an option.
At least, not until Capt Picard says it is.
I can't look at that any more. It hurts my eyes.
I can't think. My mind feels like it's wrapped up in a blanket.
- Take a break. I'll work on this. - I don't need a break!
I need to get off the ship.
Susanna, why don't we... go and see Dr Crusher?
Forget Crusher and forget your logs!
Tarchannen's down there, Geordi. It's waiting for us.
That's where we should go.
Susanna,... you can't leave.
Blood pressure's still falling. Apply T-cell stimulator.
We have got to stabilize her immune system.
She has developed an extreme sensitivity to light.
We're trying to make her comfortable.
..hold on. OK?
Dr Crusher... will help you,
..so... just hold on.
It's inside of me, Geordi.
I can't fight it.
- It's winning. - Don't give up.
Do you hear me?
You can't give up, Suz.
This is one of Susanna's altered skin cells and an alien cell Data found.
Almost identical. How do you explain that?
The people from Tarchannen III who disappeared weren't abducted.
I think they were transformed into another species.
Can you stop it?
The T-cell stimulator will slow down the rate of change,
but until I find the cause...
- Is the Enterprise at risk? - No.
I checked the cell-wall integrity. Its viability is low.
- I don't think she can transmit it. - Then how did she get it?
I wish I knew.
The only thing I do know, Geordi,...
..is that it's very possible that you will be next.
I had two full bioscans today.
You said I was fine.
I gave Susanna a bioscan, too. I didn't find anything wrong with her.
Brevelle was sick for days before he left.
Mendez was normal an hour before she disappeared.
You may have weeks or very few hours.
Then there's no time to waste. I should get back to work.
Geordi, until I know what we're dealing with,
I think you should stay here in sickbay.
You said that it would help if you knew the source.
If I continue analyzing the records, I might find an answer.
Mr. La Forge,... what if you begin to change?
What if you feel compelled to go down to the planet?
Program the computer to monitor my movements.
That way we can be sure that I don't leave the ship.
What would you do, Captain?
Would you sit it out here in sickbay,
or try to learn what it is that's got you,
and maybe stop it?
Very well. You proceed with your investigation,
but report for a bioscan at the start of the day watch.
Geordi, if you have symptoms of any kind, I want to know immediately.
One to transport.
I'll make another sweep.
La Forge, building four. Mendez and Brevelle, two.
I'll take five.
Alright, Computer, analyze audio elements
from time index 1447 to 1558.
List all anomalies.
No audio anomalies present.
Any subspace projections? Z-particle emissions?
No subspace projections present. No Z-particle emissions present.
No interferometric patterns present.
May I ask how your investigation is proceeding?
- You attempted an audio analysis? - Yes, Data.
And a spectrographic analysis, and a screen for ionising radiation.
I even ran an enhancement for micro-seismic disturbances.
I've tried it all, OK?
There is no need for an apology.
Perhaps if you indulged in a brief rest period,
you could approach this problem with a fresh point of view.
You're probably right,
but I've got to keep scanning these records while I can.
May I assist you?
If I knew what I was looking for.
Really, Data,... I think it's just a matter of me going over it,
maybe finding something I forgot.
I'll let you know if I come across anything.
One more time.
- Sorry to disturb you... - What's happened?
I thought you should see this.
Her skin is simulating light!
A radiant reaction. Some sort of mimetic ability?
That's not all. Her body temperature is dropping.
It's as if she's generating a disruptive field.
I can barely get any readings off her.
- Her rate of transformation? - Increasing.
Impossible! It should have been inhibited by the T-cell stimulator.
If there's a foreign body inside her that's producing these changes,
something like a viral créche.
A very small one if our scans haven't found it.
I want a full genetic analysis.
We'll examine any abnormality, no matter how insignificant it seems.
- One to transport. - Computer, delete the audio.
Wait a minute. Freeze visual.
- Whose shadow is that? - Please restate question.
Computer, the shadow currently displayed
in section B-3, what is its source?
Come on, it's gotta belong to somebody.
Computer, replay a visual of the last time index.
No audio,... and slow to 50 percent.
Brevelle's behind the camera. Susanna and I head off
in that direction. Mendez moves off that way. Freeze visual.
Now,... magnify four times.
And spectrally enhance those shadows.
Do you have sufficient data to compile a holographic simulation?
A simulation would be limited to areas scanned by the recording.
Fine. Scan the entire record and recreate it on holodeck three.
Computer, is the Tarchannen simulation ready?
Affirmative. Program complete. Enter when ready.
Computer,... scan Starfleet records and create a simulation of Brevelle.
Place him where he was while recording this.
Computer, based on their speed and direction,
can you extrapolate each one's movements
as they walk out of the recording device's field of view?
Affirmative, with an increasing probability of error
reaching 95 percent after ten seconds.
Understood. Run simulation.
I want to make another sweep.
La Forge, building four. Mendez and Brevelle, two.
I'll take five.
It's all happening too fast. Computer, reverse simulation.
Run it back to time index 1472.
Computer,... remove La Forge.
And... now remove Leijten.
And now... remove Mendez.
Computer, using vector analysis, identify the source of this shadow.
There is no object in the program which could generate the shadow.
..there has to be something
between the camera light and this wall.
..given the distance between the light and the wall,
can you determine the most likely shape and position
of the object causing this shadow?
Insufficient data to reconstruct the requested object.
Let's say that my friend and I here are about the same size, say...
1.7m. Now, can you extrapolate its shape and its position?
- Affirmative. - Do it!
There, in the thymus.
Some sort of parasite.
It's using Susanna's immune system to spread genetic instructions.
- How did it get there? - Maybe during the original mission.
It's small enough to enter through any mucous membrane.
But it isn't behaving like a typical parasite.
It isn't feeding off of her. It transforms her DNA to match its own.
There's not much of her original DNA left.
We're gonna need unaltered genes or we're never gonna get her back.
We've got to get that thing out of her now.
- Any luck? - Negative, Commander.
Nothing suggests the source of a parasitic infection.
Crusher to bridge.
- Go ahead, Doctor. - The surgery was successful.
It'll be a few hours before we know
whether her regenerative systems are responding.
In the meantime, we better get La Forge down here.
- Keep us informed. - Crusher to La Forge.
Computer, locate Cmdr La Forge.
Cmdr La Forge is not on board the Enterprise.
Bridge, the computer says La Forge is no longer on board.
Is that correct?
I am showing no transporter activity.
All shuttles are secure.
No indication he's left the ship.
- Last known location of La Forge? - Holodeck three.
If Geordi has transformed, he may be a chameleon.
The skin develops mimetic capabilities.
He may still be on board, but undetectable to our sensors.
You search the structure. I will take the perimeter.
Security, intruder in transporter room six!
The security lock-out on transporter room six has been broken.
I cannot. The transporter cycle has already begun.
Captain's log, star date 44668. 1.
Dr Crusher's research indicates we have less than an hour
before Cmdr La Forge's transformation becomes irreversible.
However, all attempts to locate him on the surface have failed.
I do not read any life signs on the surface.
Our sensor array is useless. We must find another way of locating him.
If we can get close enough to Geordi,
we can read his spectrum with an ultraviolet light.
Can you modify an emergency beacon to operate on UV?
- Yes, sir. - Make it so.
As soon as Data is ready, I want you to lead an away team.
How long, Data?
I must replace the emitter module and reconnect the power supply.
It will take two minutes to complete the modifications.
- Hendrick to Cmdr Riker. - Go ahead.
I've determined La Forge's transport coordinates.
He beamed down next to the Aries shuttle.
He's on foot. He can't have got far. Let's assume a radius of... 10 kms.
That still leaves a search area of more than 300 square kilometres.
We've got to narrow that down. The enhanced sensor arrays?
All scans are still negative.
We've got to find a way to track him. The high-resolution EM scan?
We are adjusting sensors to read his absorption spectrum,
- but it will take several hours. - Geordi doesn't have several hours!
I have completed modifications.
Excellent. Dr Crusher, meet us in transporter room six.
He's gonna need a sedative. Give me 10 ccs of kayolane.
- You look a lot better than you did. - What did you do?
Removed a parasite from your thymus.
No, it's not a parasite, Doctor.
It was their method of reproduction, to plant a DNA strand
in a living host that causes metamorphosis. Geordi?
- He's gone? - Yes.
- Back to the planet? - Stay calm.
- We have to find him. - An away team is searching.
You'll never be able to find him. I'm the only one who can.
No, turn them off, the light frightens them.
- What about UV? - Beyond their visual spectrum.
They won't run away from it.
He could be several kilometres away.
No, he's here. They're all here.
Geordi. Geordi, my voice is familiar. Listen to it.
You can feel that we share this. You know I'm not a threat.
The others, Mendez, Brevelle,... they don't exist as humans any more,
but a part of you still does.
You're not one of them yet, Geordi.
I can help you if you'll just trust me.
I know what's going on inside of you,...
the war you're fighting with yourself,
your humanity slipping away. The instinct to run,
But they know how to beat it now, Geordi.
Look at me!
I've come back, Geordi.
Let me take you back, too.
Just take my hand.
Enterprise, lock onto Cmdr Leijten's signal.
Prepare to beam two to sickbay.
We're going home, Geordi.
Is there no hope for Brevelle or Mendez?
- Susanna. - I'm right here, Geordi.
So are Dr Crusher and Capt Picard.
Here's your visor, Geordi.
Lt Cmdr La Forge reporting for duty, Captain.
Welcome back, Mr. La Forge.
Geordi, this species, can you communicate with it?
No. They... act on instinct alone.
In another few minutes, I wouldn't have responded to you, Susanna.
Then we will leave them be.
I'll order warning beacons placed in orbit and on the surface,
so no one else goes through what you did.
You know,... down there, l... didn't know who you were.
And yet,... somehow,...
..l believed you, I trusted you.
That must have been because of all the good advice I used to give you.