Plot: A man seeking the grail comes to Babylon 5 to query the alien ambassadors about it. He takes under his protection a former B5 construction worker who thinks he's cursed to cause the Babylon stations to be destroyed. The construction worker is being threatened by a smuggling boss from Down Below who got his hands on a Centauri-connected mind-wiping monster who he's dressed up in a copy of Kosh's encounter suit.
The grail seeker dies protecting the former construction worker, who becomes a new grail seeker. The mind-wiping alien is killed; the smuggling boss gets away.
Kosh quote with extra meaning in hindsight: Sinclair: "Well, after all, no one knows exactly what you look like. That makes some people a little nervous." Kosh: "Good."
Comment: Three guest stars in one episode! The grail seeker is played by David Warner; the smuggling boss you might not count since he doesn't get that much time, but he's played by William Sanderson, so he totally counts.
So yeah, it's kind of a dumb guest star episode, but at least everything connects better to Babylon 5 culture and characters. The Minbari honor the seeker for being true to his cause. I think this may be the first reference to Down Below explicitly. Londo is a coward, Ivanova is a pessimist. Sinclair does some action hero-y gunfighting that I still just don't buy.
William Sanderson's character gets away at the end and everyone just kind of forgets about him after that (since they're focused on the monster). Apparently he shows up again in the movie Thirdspace, which was shown during(?) the fifth season but is set in the fourth season. Maybe they'll mention his character now and then throughout the series.
But the fake-Kosh bit is dumb and pointless (it feels like a setup that should have been used for something more substantial).
Sorry for a terrible, boring post.