the story: Odo's secret love for Kira becomes less easy to hide when her latest lover, Shakaar, shows up at the station.
what it's all about: The subplot of the Odo/Kira relationship was a slow boil during the series until it finally exploded in the sixth season and became a crucial element of the final episode, "What You Leave Behind." "Crossfire" is the episode where it starts to bubble to the surface in dramatic fashion.
"Heart of Stone," from the third season, was really when what had been subtext to that point became something more obvious when the Female Founder tricks Odo into revealing why he really prefers to stay among the "Solids" (what the Founders call humanoids who can't change shape) rather than reunite with his people. "Crossfire" has nothing to do with the emerging Dominion threat but instead harkens back to a comparatively more innocent age of the series, when "mere" Bajoran matters still mattered for reasons other than Kai Winn's meddling. Shakaar, who debuted last season in an eponymous episode, was created to replace the relatively lifeless Bareil, who had probably come to symbolize the apparently bloodless Bajorans for a lot of viewers in the early seasons. But this is Shakaar's second and last notable appearance, and his appearance isn't really about him at all, but an excuse for Odo to finally realize just how much he really cares for Kira.
Comparable to the torture sequence in "The Die is Cast," "Crossfire" eventually finds Odo in the most disheveled state we've ever seen him (again, except for that torture sequence), his hair out of place and everything, and having destroyed the quarters he's recently begun inhabiting despite needing only a bucket to regenerate in (this progress was, of course, prompted by Kira)...
Basically, this is a really excellent episode for fans of the series. Deep Space Nine increasingly centered its focus on its own fans rather than Star Trek fans in general, which was to eventually make it a "cult within a cult," and it's thanks to episodes like this one where that was possible. The fourth season began as an experiment to see how far back into general Star Trek fun the series could be pushed after the strong serialization efforts of the third season, but by this point the producers had realized what really worked, and "Crossfire" represents the shift back to the slow march to the way everyone remembers the series, the heavy serialization of the final seasons intermixed with "standalone" episodes that still were mostly relevant to series matters first and foremost.
franchise- If you're a casual fan this episode probably won't apply to you.
- series - Long-term fans will eat it up.
- character - Most important as an Odo episode.
- essential - But of course it deeply informs his later relationship with Kira.
Duncan Regehr (Shakaar)