McCoy: So why is this episode called "Albatross"?
Kirk: Well, that would be an allusion to Samuel Taylor Coleridge's epic poem The Rime of the Ancient Mariner, in which a sailor shoots an albatross, a terrible act which curses him and his ship. He feels the metaphorical weight of guilt, as if the dead albatross was slung about his neck.
McCoy: I see. Well, I certainly felt potentially guilty for a bit.
Spock: But you were completely innocent of any wrongdoing. The allusion does not—
Kirk: "Yea, slimy things did crawl with legs, Upon the slimy sea."
Spock: Perhaps it refers to the illegal act of breaking McCoy out of prison to—
Kirk: Albatross!!

Transcript

1
Captain's log, Stardate 5275.6. Delivering medical supplies to Dramia.
Demos: Dr McCoy. You are under arrest for spreading plague on Dramia II, 19 years ago.
McCoy: PLAGUE??
2
Spock: {to McCoy} Your defence rests on the fact that you don't like plagues.
Kirk: You're doomed, Bones.
3
Sulu: Dramia II. There's an aurora that changes the colour of things.
Kirk: The alleged plague world. Let's beam down with no biohazard precautions!
4
Kol-Tai: The plague changed people's colour. I survived because McCoy treated me for Saurian virus.
Kirk: So he's innocent. Huh.
5
Kirk: {blue skin} The entire crew is infected! Spock, break Bones out to find a cure!
Spock: I may carry the plague to Dramia.
Kirk: Eh.
6
McCoy: It was caused by the aurora! Saurian virus antibodies cure it!
Spock: Auroras do not work that—
McCoy: PLAGUE!!