When in doubt, and crafting a Trek episode, give the sets group a call and tell them you’re dragging out the cave system again. No other location, except perhaps Californian woodland, has seen so much screen time as an off-world locale in this franchise’s history.

Odo and Kira, returning from another one of those conferences we always hear about but never see, run afoul of a marauding Maquis, and pursue him to planet Sensor Disruption IV. On-world, they commit the AD&D faux pas of splitting the party, and the entire situation falls apart as Kira gets her foot trapped in a crystal. Said crystal is growing.

Elsewhere, we’re treated to a B-plot of Nog deciding to join up with Star Fleet. To even have a chance, he has to get a letter of recommendation from Sisko. Nog’s decision is surprising, since so far he’s been used by the show as a court jester completely immersed in Ferengi womanizing and maneuvering. But in this episode, suddenly he decides to give that stuff up.

Both plots wind up working, and how.

The situation in the cave leads to a number of revelations, some of which had my darling wife in absolute joy. Nana Visitor and Rene Auberjonois completely sell the growing tension as Kira is slowly swallowed by the crystal. There are moments of longing from Odo. Soul-baring, almost tear-jerking details of his past come to the front.

Then it comes crashing down, with a subversive twist I didn’t see coming. Well played, writers.

Some viewers might say this is a cop-out, and that it renders everything Odo went through as so much gristle–it doesn’t advance the flavor of the series. I disagree. What happened was completely appropriate for the characters involved, and gives us a window into one of the series’ most tortured characters. Just because the plot seems like it doesn’t advance–that doesn’t mean the characters don’t.

Nog’s long journey (I hope) in Starfleet begins with grunt work, but he keeps a good attitude through it all. I found myself rooting for him, and hoping he’d get past his challenges. This episode effectively uses Nog’s request as a test of Sisko’s prejudice against Ferengis, too. The commander isn’t perfect, and has to come face-to-face with his own misconceptions.

By the time things finally settle, the episode has left us with a holy trinity of character development, intrigue, and further questions. That makes this a solid mid-season entry, and one of the show’s strongest episodes to date.

Rating: 4/5 stars.