Deep Space Nine's Dominion War arc are planted here, with the Dominion themselves name-checked in DS9 season 2, episode 7, "Rules of Acquisition", and the Dominion's soldiers debuting in DS9's season 2 finale, "The Jem'Hadar".

Amid these hints of what's to come, Star Trek: Deep Space Nine's second season strongly emphasizes identity as a theme, asking who the main characters of Star Trek: Deep Space Nine are, and examining what they stand for. That makes it tough to pick out which season 2 episodes of DS9 are truly skippable, because even the shakiest standalone episodes manage to drop important lore about characters' personal and cultural backgrounds. But we're still a long way off from peak DS9, so you can skip these if you need to.

5 Star Trek: Deep Space Nine Season 2, Episode 4 - "Invasive Procedures"

Dax Skips This Brief Host, So You Can Skip This Episode

Star Trek: Deep Space Nine season 2, episode 4, "Invasive Procedures", is a bottle episode that has no real, lasting consequences in the end, so you can skip it. Verad (John Glover), a Trill who was rejected for ing, takes advantage of Deep Space Nine operating on a skeleton crew during an evacuation so that he can steal the Dax symbiont. After Verad successfully removes the symbiont from Jadzia Dax (Terry Farrell), Jadzia doesn't have long to live — but the stakes are practically nonexistent because Dax is a main character. Jadzia just isn't in any real peril.

"Invasive Procedures" features Tim Russ, who would go on to play Star Trek: Voyager's Tuvok, as a Klingon mercenary.

More to the point, the Verad of it all just doesn't stick. Near the end of "Invasive Procedures", when Dax is returned to Jadzia, she explains that she has some of Verad's memories, but there wasn't enough time for the ing to really take hold. Later episodes, like DS9 season 4's "Facets", don't include Verad as one of the hosts of the Dax symbiont, and Jadzia Dax doesn't call upon Verad's memories or skills in the same way that she does for former Dax hosts like Torias or Curzon.

4 Star Trek: Deep Space Nine Season 2, Episode 9 - "Second Sight"

Commander Sisko Falls For Schrödinger's Love Interest

Star Trek: Deep Space Nine season 2, episode 9, "Second Sight", may actually be the most skippable episode of the season. Commander Sisko falls for a woman named Fenna (Salli Elise Richardson), who both does and does not exist. The mystery of Fenna's identity meanders and hits a lot of dead ends before Sisko just happens to discover that Fenna looks just like Nidell, the wife of visiting scientist Seyetik (Richard Kiley). The short version is that Fenna is a telepathic projection of Nidell, but the episode makes it more convoluted than it needs to be.

"Second Sight" was originally pitched as a Dr. Julian Bashir (Alexander Siddig) episode.

"Second Sight" was originally pitched as a Dr. Julian Bashir (Alexander Siddig) episode, which would have made it a little more believable. Bashir is falling for a new woman every third episode, it seems, whereas Sisko would mesh more realistically with a love interest who's more grounded and substantial. No matter how well Brooks sells it, it's hard to get on board with Sisko being so immediately infatuated with a mystery woman. Even before we learn that she's an illusion, Fenna doesn't feel real enough for Sisko to legitimately fall in love with her.

But making "Second Sight" a Sisko episode does result in one noteworthy character development. Falling for Fenna, even if she's an illusion, is proof that Benjamin is no longer so trapped in his own grief after the death of his wife, Jennifer Sisko (Felecia M. Bell). It's an important note, to be sure, since the Prophets pointed out how grief kept Sisko emotionally locked in the Battle of Wolf 359 back in Deep Space Nine's series premiere. But that's not worth the inconsistencies and incoherence of the rest of this episode.

3 Star Trek: Deep Space Nine Season 2, Episode 10 - "Sanctuary"

"Sanctuary" Tries To Be Too Many Stories At Once

Star Trek: Deep Space Nine season 2, episode 10, "Sanctuary", isn't a total miss, but this episode doesn't bear the full weight of the story it's trying to tell, either. A new alien race, the Skrreeans, comes through the wormhole believing that they've been divinely guided to settle Bajor. Early scenes are spent on the Skrreean language not working with the universal translator, so it seems like "Sanctuary" will be about Major Kira Nerys (Nana Visitor) learning to communicate with the Skrreean matriarch Haneek (Deborah May). But "Sanctuary" pivots to developing the Skrreean culture, like they'll be coming back later.

Instead, "Sanctuary" buries the lede, and sidesteps the political parallels that should make this a stronger Star Trek episode than it is. The Skrreeans turn out to be refugees, which makes Major Kira Nerys (Nana Visitor) and Commander Sisko sympathetic to their plight, but the Cardassian Occupation of Bajor left the planet without the resources to Bajorans, let alone an entire planet of refugees. The Skrreeans reluctantly accept the Federation's alternative plan, and we never hear from them again.

2 Star Trek: Deep Space Nine Season 2, Episode 11 - "Rivals"

"Rivals" Is A Lighthearted Bit Of DS9 Fluff That's Okay To Skip

There are things to like about Star Trek: Deep Space Nine season 2, episode 11, "Rivals", but the episode's core conceit falls apart on closer examination. To Quark's (Armin Shimerman) dismay, newcomer Martus Mazur (Chris Sarandon) opens Club Martus, a gambling house populated with probability-altering games that inexplicably interfere with the station's good and bad luck. The B-plot about Julian Bashir and Chief Miles O'Brien (Colm Meaney) as racquetball rivals neatly loops into the A-story via Quark's betting pool — but Bashir and O'Brien aren't Star Trek's best friends just yet.

Bashir and O'Brien's long-lasting friendship gets its actual start just a few episodes later, in Star Trek: Deep Space Nine season 2, episode 13, "Armageddon Game".

If you can forgive the idea of a luck machine stretching credibility, "Rivals" is an okay Star Trek: Deep Space Nine episode that doesn't take itself too seriously. You won't get a scientifically sound explanation for the probability-altering machine, because it's just there to put Bashir, O'Brien, and Quark into situations where they have rashes of alternating good and bad luck. It's a low-stakes DS9 episode light on the drama, but it doesn't reach the height of Star Trek comedy episodes either, so you can get away with skipping "Rivals" if you want to.

1 Star Trek: Deep Space Nine Season 2, Episode 18 - "Profit and Loss"

Quark's Single-Episode Love Story Misses The Mark

Curiously, Star Trek: Deep Space Nine season 2, episode 18, "Profit and Loss" has Quark seemingly miscast in his own story. I like the idea that there's more to Quark than what his criminal reputation would have us believe. "Profit and Loss" tries to do that by reuniting Quark with his lost love, Natima Lang (Mary Crosby), a Cardassian teacher and political dissident. Star Trek: Deep Space Nine has previously shown us that Quark does secretly care about people in his own way, so there's merit in pursuing that characterization. But there's something missing in the execution.

DS9 will give Quark another chance at a more believable love story in Star Trek: Deep Space Nine season 5, episode 3, "Looking For Par'mach In All The Wrong Places", when he reunites with his Klingon ex-wife, Grilka (Mary Kay Adams).

It's not clear if Quark's motives are meant to be honorable or an extension of Quark's shrewd values, built on the Ferengi Rules of Acquisition. Quark helps Natima's students for seemingly altruistic reasons, while asking Natima to stay on the station despite the danger to her is a self-centered move. Natima has never been mentioned before, and Quark's previous treatment of women is so misogynistic that it feels disingenuous at this point in Star Trek: Deep Space Nine to push Quark as a romantic lead. I get what "Profit and Loss" tries to say, but it's not working.

Ultimately, season 2 of Star Trek: Deep Space Nine is a marked improvement over Star Trek: Deep Space Nine season 1. There's an upward trajectory that will only continue in future seasons, and eventually make DS9 the most tightly-plotted and morally gray Star Trek series of the Berman era. But the second year of Star Trek: Deep Space Nine is also a little shaky in places. Skipping these episodes will help Star Trek: Deep Space Nine season 2 feel a little more tightened-up, like the Star Trek show that we know it will become.