Commander's Log, Stardate 48959.1.
It is with mixed emotions that I record this
my final Commander's Log.
The last three years have been
the most demanding and rewarding of my career.
I can only hope that the future will hold
even greater challenges.
Dad, there's something I've been wanting
to say to you for a long time.
And now that I finally have the chance
I'm going to make it short and simple.
Congratulations...
Captain Sisko.
Well, now that you have another pip on your collar
does that mean I can't disagree
with you anymore?
No, it just means I'm never wrong.
Oh, we'll see about that.
Curzon would have been proud of you
but not as proud as I am.
That means a lot to me, Dax.
Though I don't fully understand
this humanoid obsession with rank and title
if anyone deserves to be promoted, it's you.
Thank you, Constable.
Well, as someone who is obsessed with rank and title
congratulations, Captain.
That goes for me, too, Captain.
This calls for a toast.
BASHIR: That better not be from a replicator, Quark.
Chateau Cleon, 2303.
I already put it on your account.
Can I?
I guess a sip won't hurt.
Well...
Here's to the newest and best Captain in Starfleet
and all I can say is, it's about time.
Hear, hear. Hear, hear.
Cheers.
Ah, ah, that's, that's enough.
Thanks for coming, Ambassador.
Those pips look good on you, Captain.
Though, to be honest
I'm not really here for the ceremony.
I had that feeling.
What can I do for you?
Our intelligence reports indicate
there's been a coup d'état on the Tzenkethi homeworld.
I doubt anyone is going to miss the Autarch.
I know I won't.
Unfortunately, it's too early to tell who's in control
but we don't want to take any chances.
We need to remind the Tzenkethi
that the Federation is committed to protecting
our colonies near their border.
You want to show the flag.
Exactly.
The Defiant will leave in two days on a week-long patrol.
I'll be coming along as an observer.
I've heard a lot about the Defiant.
I'm looking forward to seeing her in operation.
I don't think you'll be disappointed.
She's a fine ship.
With a fine crew.
Now what do you say we get back to the party?
Of course.
ALL: ♪ For he's a jolly good fellow ♪
♪ For he's a jolly good fellow ♪
♪ Which nobody can deny. ♪
O'BRIEN: Hip, hip...
ALL: Hooray!
Hip, hip... Hooray!
Hip, hip...
Hooray!
( applause )
I want a complete overhaul
of the deflector shield generators
and targeting sensors.
Oh, yes— take on a full complement
of photon torpedoes.
Don't worry, Captain.
If the Tzenkethi try to start any trouble
we'll be ready for them.
I don't doubt it, Chief.
( clattering and thumping )
Captain?
( sighs )
Getting jumpy in your old age, O'Brien.
Captioning sponsored by PARAMOUNT PICTURES
SISKO: My son, the writer, thinks I should say
something profound on this occasion.
He even offered to write me a brief statement.
I told him I'd take care of it myself.
But as it turns out, the only thing I can think of is:
Begin Captain's Log, Stardate 48960.9.
So, have you told her yet?
Told who?
Captain Yates.
About your promotion.
Yeah, I barely had time
to send my father a transmission.
In fact, I don't even know where Kasidy is.
She's hauling a load of duridium ore to Solais V.
Oh.
You could probably contact her on subspace.
I'd rather tell her in person.
When's she due back on the station?
About a month.
A month?
Ah, there's nothing worse
than a long-distance relationship.
I wouldn't call it a relationship, Dax.
I've only taken her out once.
Okay, twice.
I think the exact figure is three times.
She's quite an interesting woman.
She's very independent, a little opinionated
but she has a nice sense of humor.
And...?
And? What do you want me to tell you, Dax?
That you miss her.
That you can't wait to see her.
I don't know. Anything.
Kira, O'Brien, Bashir
they're all dying of curiosity, and...
well, I have to tell them something.
Fine. You tell them when she gets back
I'm going to take her to the holosuite
and we're going to watch
the seventh game of the 1964 World Series.
You do like her.
Captain on the Bridge.
Ambassador.
Captain.
All stations, report.
Helm ready.
Weapons ready.
Communications systems standing by.
Warp and impulse engines are on line.
Seal the airlock, release docking clamps.
Docking clamps released.
Engage thrusters.
Clearing the station.
Lay in a course for the Tzenkethi border, warp eight.
Aye, aye, Captain.
Engage.
( rumbling creak )
Hello?
Who's there?
( clattering thumps )
Julian!
You called me, Chief?
Why didn't you answer me?
I had this spanner in my mouth.
What are you doing here, anyway?
I was connecting my new diagnostic console
to the Medical Bay's power grid.
Well, I could have done that for you.
Oh, just putting my engineering extension courses to work.
Besides, I know you have your hands full.
Oh. Where are you going now?
I'm done.
Huh.
Not bad for an extension course.
You wanted to see me, sir?
Yes, Commander.
It's about Ambassador Krajensky.
Please.
I know Starfleet doesn't intend
for this to be a combat mission.
But just in case the Tzenkethi have other ideas
I want make sure the Ambassador is kept out of harm's way.
Yes, sir.
I'll see to it that, if hostilities do occur
the Ambassador is escorted off the Bridge.
He won't like it.
I won't let that bother me.
Very good, Commander.
That will be all.
Captain.
I just want to say that...
I agree with what Chief O'Brien said
about your promotion.
It's about time.
I appreciate the sentiment, Commander
but it really doesn't change anything.
I have the assignment I want. I have the crew that I want.
The rank doesn't make much difference.
You'd be surprised.
People don't enter Starfleet to become Commanders
or Admirals, for that matter.
It's the Captain's chair that everyone has their eye on.
That's what I wanted when I joined up, but...
you don't get to be a Captain wearing a gold uniform.
You could always transfer from security to command.
Then who would protect the Ambassador?
Dismissed, Mr. Eddington.
Thank you, sir.
Captain's Log, Stardate 48962.5.
We are 12 hours from the border.
I haven't been in this area
since the last Federation-Tzenkethi war.
Being here brings back a lot of memories, most of them bad.
( console beeping )
Captain, we're receiving
a priority one distress signal
from Barisa Prime, audio only.
Put it through.
MALE ( staticky ): Under heavy fire
from Tzenkethi warships.
I don't know how much longer we can hold out.
Can anyone hear me?
This is...
( transmission cuts off )
Constable?
We've lost contact.
Try to reestablish.
It's no use, Captain.
They're gone.
Captain's Log, supplemental.
We've been unable to reestablish contact
with Barisa Prime.
Therefore, I've no choice but to assume
we are at war with the Tzenkethi.
Lieutenant, set a course
for Barisa Prime, maximum warp.
I want continual scans for Tzenkethi ships.
Constable, contact Starfleet Command.
Let them know what happened.
Major, what other starships
are in this sector?
The closest one is the Ulysses.
They're studying
protoplanetary masses
in the Helaspont Nebula.
That puts them...
20 hours away at maximum warp.
Lieutenant, transmit a message to Captain Entebe
on the Ulysses.
ODO: Captain, I'm having trouble
getting through to Starfleet Command.
There seems to be a power fluctuation
in the communications system.
I can't get a message out, either.
The console is functioning normally.
The problem must be in the transceiver assembly.
I need that system back on line, Chief.
I'll get on it right away.
Lieutenant, I could use some help.
Major, take the helm.
Yes, sir.
What do you make of this, Lieutenant?
I've never seen anything like it.
It's spreading
through the system like some kind of parasite.
It seems to be linked to key points
within the transceiver assembly.
Better get it out of there.
( cries out )
A force field.
Come on.
Where are we going?
I want to check the other command systems.
I have a bad feeling about this.
SISKO: You say these things are all over the ship?
O'BRIEN: They've attached themselves
to the command and communication relays
the internal sensors, the transporter
the deflector shield grid—
almost every critical system.
Is there any way to get past the force fields?
None that we've found yet.
We're still working on it.
Hmm.
Well, I guess the question is
how did they get aboard?
Or should I say
who placed them here?
Well, I don't know who did it
but I know it definitely happened
after we left the station.
I ran a systems check before our departure.
They weren't there then.
Which means someone aboard this ship is a saboteur.
We've got 47 people on board.
Theoretically, any one of them
could have planted those devices.
Chief?
It's nothing, sir.
It's not even worth mentioning.
It doesn't sound like you're too sure about that.
Well, I did see someone
crawling about in one of the Jefferies tubes
the other day.
Who?
It was Julian.
He was connecting
a medical console to the power grid.
Which is right next to the communications relay.
Are you accusing Julian of sabotage?
No one's accusing anyone of anything, I...
But I want to talk to Julian.
Wait.
I think I have a better idea.
This crew has been through a lot together.
In fact, I would trust any one of you with my life.
But after looking at the evidence
there's only one conclusion I can draw:
Someone on this ship is guilty of sabotage.
With your permission, Captain, the Constable and I
can begin questioning the crew immediately.
That won't be necessary.
Lieutenant?
We found one of the devices
planted in the warp plasma conduit
which means whoever put it there
would have been exposed to trace amounts
of tetryon particles.
And those particles would still be detectable on the saboteur?
Yes, but not for much longer.
They dissipate quickly.
So you're going to scan
all the members of the crew for tetryon particles.
Starting with the senior staff.
O'Brien and I already scanned positive
since we opened up the warp core controls
during our investigation.
You realize, of course, that if no one else tests positive...
We'll be the prime suspects.
Yes, we know that.
We might as well get started.
You're clean.
I'm glad to hear it.
Might as well do me next.
You're okay, too.
Julian.
Hmm?
Of course.
Nothing.
You sound relieved.
Well, I am.
After all, you were in that conduit
the other day.
Ambassador, if you please?
Certainly.
BASHIR: I was never in any conduit.
Of course you were.
I saw you there.
It's a changeling.
We've cloaked.
Lieutenant, bring us out of warp.
Full stop...
now.
Constable, Commander...
deploy security teams immediately.
I want that changeling found
before he can do any more damage.
Yes, sir.
Captain, the helm's not responding.
We're still at warp.
I can't deactivate the cloaking device.
The weapons array is activated.
The phaser banks
are charging.
And we've got photon torpedoes on line and ready to launch.
The ship's no longer
under our control.
Our security teams have gone over
every centimeter of the ship
checked every piece of cargo
questioned every crew member.
We still haven't been able to find the changeling.
Is there any way he could have been
transported off the ship?
At warp?
It's unlikely, but...
with Dominion technology
I suppose it's possible.
He's still here.
He won't leave until he's completed his mission.
Which is?
It looks like the Dominion is hoping to start a war
between the Federation and the Tzenkethi.
KIRA: Well, if you ask me, the Tzenkethi
are doing a pretty good job of that all by themselves.
SISKO: Not necessarily.
The transmission
we received from Barisa Prime could have been faked
using that device we found implanted
in the communications relay.
In fact, our entire mission could have been
engineered by the Dominion.
Think about it.
We've been all over this ship and we have not seen a trace
of the real Ambassador Krajensky
nor his remains.
Which means, he was probably replaced
before we left the station.
Maybe the real Ambassador
never came to Deep Space 9 at all.
So everything Ambassador Krajensky told us
could have been a lie—
the Tzenkethi coup d'état
increased tension along the border
the threat of an attack.
And now, here we are, cloaked
armed for battle
and heading into Tzenkethi space.
If we can't stop this ship
before we cross the border
we may wind up causing a war
rather than preventing one.
Which is, no doubt what my people are hoping for.
A war between the Tzenkethi and the Federation
would destabilize the Alpha Quadrant
making it that much easier
for the Dominion to move in.
EDDINGTON: I wish the internal sensors
were on line.
It'd make it a lot easier to track down the changeling.
ODO: I'm not sure the sensors would help.
If you scan me while I'm a rock, you'll detect a rock.
I may not be able to duplicate a humanoid perfectly
but I'm guessing he can.
We scanned Krajensky for tetryon particles.
He registered as human.
KIRA: Well then, right now
the changeling could be anything...
or anyone on this ship.
Then we have to narrow his options.
Confine
all nonessential personnel
to their quarters
and seal them in with force fields.
Doctor, I want you to review
all the tricorder readings.
See if you can find anything
that will help us find the changeling.
And take some security with you.
From here on, no one is to be left alone.
We have seven hours before we enter Tzenkethi space.
I want that changeling found before then.
EDDINGTON: That won't be easy.
Let's face it, no matter how many precautions we take
he could replace any one of us
and we won't know it until it's too late.
Thank you for your cooperation.
Hopefully, this will be over soon
and you'll be able to return to duty.
All right, let's go.
This may take a while.
Keep your phasers on stun
and stay calm.
I don't want anyone getting nervous
and shooting one of us by mistake.
You sure I can't interest you in one of these?
I don't use them.
Besides, in the history of my people
no changeling has ever harmed another.
I'd hate to be the first.
Apparently, that changeling doesn't feel the same way.
If we don't stop him
no one on board will escape unharmed, including you.
You may be right.
But I've been a security officer
most of my humanoid existence
and in all that time, I've never found it necessary
to fire a weapon or take a life.
I don't intend to start now.
This is O'Brien.
I need a security team in the Engine Room immediately.
It must have been the changeling.
I went down the hall to get an interphasic compensator.
I heard a noise, and when I came back...
She has a severe concussion.
Give me a hand.
We've got to get her to the Medical Bay immediately.
Stay here with the Chief.
Damage control team, report to the Engine Room.
Aye, sir.
( sighs )
Dax is still unconscious.
I've given her cortical analeptics
to stabilize her condition.
She should be all right in a day or two
but until then...
Is there any way to speed up the process?
I could use a neural stimulator
but that might cause irreversible brain damage.
I don't recommend it.
Then Chief O'Brien is going to have
to regain control of the ship without her.
I'm afraid so.
I should get back to my patient.
The changeling's very clever.
Taking Dax out makes O'Brien's job a lot harder.
One thing's for sure.
We're not going to start a war with the Tzenkethi.
If O'Brien can't regain control before we cross the border
I'll have no choice but to destroy the Defiant.
Our objective is simple.
Find the changeling and stop him
before he can do any more damage.
We'll break into two-person teams.
Each team will be armed with phaser rifles.
EDDINGTON: Now, we've reconfigured the rifles
ODO: Phasers have been set
low enough to prevent damaging equipment
but high enough to affect the changeling.
SISKO: The changeling
could be hiding anywhere.
He could look like anything.
So we're going to have to systematically
sweep the ship with phaser fire.
Every conduit, every corridor.
If he's out there, we'll find him.
Any questions?
What if the changeling's not out there?
What if he's one of us?
SISKO: That's why everyone
will be in teams.
Keep your partner in sight at all times.
And if we see anyone without a partner?
Escort them to the brig.
We don't want to take any chances.
Let's go.
All right, let's go.
After you.
Don't you trust me?
No, I don't.
I know exactly how you feel.
Follow me.
( sighs )
Don't you ever sweat?
No, I don't.
It's the modified phaser beam.
It's heating up the air.
Hmm.
You know, this would be a lot easier
if we knew where he was hiding.
Where would you be if you were him?
I wouldn't know.
I'm not him.
He is one of your people.
Now, can't you put yourself in his position?
Try to anticipate his next move?
I've thought about it, but the truth is
I don't understand my people all that well.
That's too bad.
Yes, it is.
For all of us.
( whispering ): Watch my back.
Over here.
On three.
One...
two...
( groans )
This is Sisko.
The changeling is in Jefferies tube 7-A
heading to the lower deck.
I'm in pursuit!
The changeling...
he's right over there.
Put your phaser down.
It's me, Kira.
We were on our way
to meet you and we got separated for a second.
The next thing I know, he opens fire.
BOLIAN: You can't fool me.
You're the changeling!
I saw you come out of that hatch and go around the corner!
I didn't see anyone!
What...
Maybe he morphed into the ventilation system...
or maybe he didn't.
For all we know, you may be the changeling.
Keep back!
Both of you, put your weapons down now!
I can't do that, Captain.
You heard him!
What happened?
How long have the two of you been apart?
At least a minute.
Then we've got a problem.
Any one of us could be the changeling.
You, Kira, Eddington, even me.
Not you.
What do you mean?
You're bleeding.
I cut my hand when the changeling attacked me.
What are you getting at?
When blood leaves a humanoid body, it's still blood.
But when any part of me separates
from my body...
It reverts back to a gelatinous state.
Sisko to Bashir.
This is Bashir.
Doctor, meet us in the Mess Hall immediately.
This shouldn't take long.
Satisfied?
So far.
Who's next?
I'll go.
I'd say the Major is exactly who she appears to be.
Try not to look so surprised.
in obtaining a sample from the Constable.
I guess that just leaves the three of us.
Let's get this over with.
You better come with us.
This is ridiculous.
I'm not the changeling.
If I were, don't you think
I'd put up a little more of a fight?
Inside.
You're making a mistake.
Do as he says!
BASHIR: Will someone
please get me out of here!
Bridge to Captain Sisko.
Sisko here.
Sir, we're entering Tzenkethi space.
Any sign of Tzenkethi ships?
Sensors aren't picking up any warp signatures.
We've altered course.
Our new heading is 015 mark 47.
We're headed directly
for the Tzenkethi settlement on M'kemas III.
How long before we're in weapons range of the settlement?
12 minutes.
Computer.
This is Captain Benjamin Sisko.
Initiate autodestruct sequence.
Authorization: Sisko-alpha-one-alpha.
COMPUTER: Identity confirmed.
Additional authorization required.
This is First Officer Kira Nerys.
Autodestruct authorization: Kira-beta-two-beta.
Identity confirmed.
Autodestruct sequence armed.
Set the countdown for ten minutes from my mark.
Authorization: Sisko-one-five destruct.
Mark.
Sequence initiated.
Autodestruct in nine minutes, 55 seconds.
Sisko to O'Brien.
O'Brien here.
I could use some good news right now, Chief.
How about this?
I think I may be able to shut down
the changeling's force fields
and gain access to the sabotaged systems.
The only problem is we may lose
our force fields, too.
COMPUTER: Autodestruct in seven minutes.
Just tell me how long it will take.
Well, I guess it'll have to be
less than seven minutes, won't it?
That'd be my suggestion.
Sisko out.
EDDINGTON: Doctor, how's Lieutenant Dax?
Still unconscious.
The changeling gave her enough sedative
to keep her under
for days.
I've managed to filter most of it
out of her system, but she'll be out
for another few hours.
I wish I could do more.
SISKO: You've done all you can
Doctor.
Now it's up to Chief O'Brien.
( sighs )
COMPUTER: Autodestruct in six minutes.
All right, we're almost there.
Now, look, when we set this device off
there's a possibility we may lose
the protective field around the warp core.
If that happens, this room's going to heat up real fast.
So give the warp core a wide berth
or you'll get a dose of radiation poisoning
even Bashir can't cure.
Where's the changeling?
I lost him in the conduits.
We haven't seen him.
Wait!
It's me, Odo.
You don't say?
Chief, remember the last time
we went kayaking in the holosuite?
You had lamb stew for lunch.
That's right.
But you forgot to bring a fork.
Anyone could have gotten that information.
COMPUTER: Autodestruct in five minutes.
You'd better make a decision.
We're running out of time.
Look, I've more important things to do
than play "choose the changeling."
Keep the phaser on both of them.
KIRA: The shuttlebay doors are sealed.
The evacuation pods are locked down.
We have no way out.
Weapons are fully charged and ready to fire.
Tactical systems are programming an attack run
on the Tzenkethi settlement.
Chief, what are you doing?
COMPUTER: Autodestruct in four minutes.
You'll see.
Now!
( alarm blaring )
COMPUTER: Warning: Warp core field breach.
Engine Room will be sealed in ten seconds.
Evacuate immediately.
Shut down the main power grid!
( screaming )
( grunts )
No!
( groans )
COMPUTER: Engine room sealed.
( gasps )
Why are you protecting these solids?
You don't belong with them.
You belong with us.
Autodestruct in three minutes.
Let go.
Don't you see? You've lost.
It's too late for you to help them
but it's not to late to help yourself.
Link with me, Odo.
We can escape together.
( laboriously ): I... don't...
Autodestruct in two minutes.
You've got to regain control of the ship!
( weakly ): Odo.
I never wanted to harm you.
( sighs )
O'Brien to Bridge.
Go ahead, Chief.
I've restored control
to the helm.
She's all yours, Captain.
Hard aport, Major.
Take us away from the settlement.
Computer, end autodestruct sequence.
Authorization: Sisko-omega-one-seven abort.
This is Kira Nerys, First Officer.
I concur.
COMPUTER: Autodestruct sequence aborted.
Phaser banks are powering down.
Take us home, Major.
Captain's Log, supplemental.
We've returned to the station without further incident.
However, I'm concerned about my Chief of Security
who hasn't said a word since we left Tzenkethi space.
The real Ambassador Krajensky
was supposed to be on his way to Risa
for an extended vacation
but he never arrived.
Starfleet Security believes he's been kidnapped
or possibly killed.
What about the coup
on the Tzenkethi homeworld?
It never happened.
Starfleet Command wants
a detailed report from each of us.
( door opens )
Odo, are you all right?
I'm fine.
I hope
I'm not interrupting.
Not at all.
Have a seat.
Captain...
there's something you need to know.
The changeling, before he... died
he whispered something to me.
Go on.
He said...
"You're too late.
We are everywhere."
Captioned by Media Access Group at WGBH access.wgbh.org