I'm almost ashamed to admit, but it was only while writing the script for this comic that I really understood what the title "Spectre of the Gun" referred to. So I put it in as a title drop here, which Spock somehow manages to avoid in the actual episode.

This episode adds Chekov to the list of main cast members who have apparently died, only to return to life later. So far this list also includes: McCoy ("Shore Leave"), Kirk ("Amok Time"), Scotty ("The Changeling"), Spock ("Return to Tomorrow").

Transcript

1
Captain's log, Stardate 4385.3. Ignored a Melkotian warning buoy because what the hell, we're here to seek out new life, whether they want to be sought out or not.
Spock: Scans did not indicate fog machines.
2
Melkotian: You ignored our warning. Captain Kirk, the method of your death shall be taken from your mind!
McCoy: Lots of women, then?
3
Kirk: It's like the Old West.
Spock: Yes, but built on a sound stage.
Syliva: {to Chekov} Billy!
4
Scotty: These have replaced our phasers!
Kirk: Six shooters. A less elegant weapon, for a less civilised age.
Spock: Yes, but when, exactly?
Caption: Chekov spends entire episode kissing Sylvia
5
{Newspaper}
Newspaper: Tombstone Epitaph
Newspaper: Tombstone, Arizona, October 26, 1881
6
Sheriff: Ike! Frank! Billy! Tom! I knew the Earps wouldn't keep you away!
Kirk: The Clanton gang! On October 26, the Earps and Clantons fought the gunfight at the OK Corral.
7
Kirk: The Clantons lost. And we're the Clantons.
Spock: History cannot be changed.
McCoy: So why did we have to return Major Nelson to 1960s Earth? Or help Gary Seven sabotage that rocket? Or let Edith Keeler die??
8
Scotty: Chekov's dead!
Kirk: But Billy Claiborne survived the gunfight...
Spock: Well, maybe history can be changed...
9
Kirk: We can't fight them with these guns. We have no training in ancient weapons. Bones, make knockout gas!
10
Caption: It doesn't work!
McCoy: We're gonna die!
Spock: This is an illusion. If you don't believe it, the bullets cannot hurt you.
McCoy: That's easy for you to say!
SFX: sniff {Scotty sniffing a jar of something}
Caption: "knockout gas"
11
Caption: Vulcan mind meld to the rescue!
Spock: The bullets are phantoms. Spectres of the gun.
SFX: Pow Pow Pow
12
{Enterprise bridge}
Kirk: Chekov, you're alive!
Chekov: That girl... so real...
Melkotian: You have passed our arbitrary test. Welcome!