Two characters talking for a long time can make for a very dull story.
But there are ways to make it fascinating.
First, if one character tells the other a story filled with conflict and engaging characters all on its own, that becomes compelling. As an example, in Fool For Love, a Season 5 Buffy the Vampire Slayer episode, Buffy's enemy Spike tells her three stories. The first two are about how he killed two vampire slayers before her.
Plenty of conflict there.
The second is his origin story. How he turned from a soft-hearted, romantic but bad poet rejected by the woman he loved into a hot vampire.
Also, there's an undercurrent of attraction between Spike and Buffy despite that they're mortal enemies. It makes us wonder – where will the evening end?
In addition, the setting and mood change as Buffy and Spike talk. And they don't just talk. They move.
First, they eat and drink beer in a dimly lit area of a bar. Then they play pool. They end by sparring in a dark alley as Buffy becomes angrier and angrier at Spike.
All of that keeps a forty-three minute episode that's mainly two characters talking fascinating.
Can you use any of these techniques in your writing?
P.S. For more on how Fool For Love is put together, listen to Buffy and the Art of Story podcast episode S5 E7 here or on your favorite podcast platform.