Star Trek: Deep Space Nine took yet another turn for the better in its fourth season, fulfilling the promise of a darker, more complicated Star Trek series. The addition of Star Trek: The Next Generation's Worf, which could have been viewed as a desperate move to boost ratings by making the show more like TNG, instead added to the depth of the series as both Worf and the Klingon Empire headed in new directions than when last seen on TNG.

Aired from October 1995 through June of 1996, many of these episodes are just as timely and compelling now (if not more so) than they were then, one of the hallmarks of Star Trek from the Original Series onward.

Below is a sampling of episodes from DS9's Fourth Season, with episodes that contributed to the larger story arc and impressive stand-alones that highlighted an individual character or theme through science-fiction storytelling which took old notions and turned them around to be seen from new perspectives. With apologies to the other great episodes of Season Four, we present our list.

The Way of the Warrior, Part I and Part II
With this two-part episode the simmering Dominion War plot arc rises to a boil and Worf joins the crew of Deep Space Nine. Featuring complex political intrigues between the Federation, the Klingon Empire, the Cardassians and the Dominion, this episode set the stage for stories and plotlines which would last throughout the rest of the series. In the second part, proving that in reality there's rarely any "happily-ever-afters," everything Worf achieved to restore his family's name in TNG is wiped away when he refuses Gowron's demands. Demonstrating how quickly political alliances and allegiances can shift, the alignment of the Star Trek universe at the end of this episode is far more treacherous and dangerous than at any time viewers had previously seen.

The Visitor
While many Season Four episodes kicked the Dominion War arc into motion or furthered it along, there were many impressive stand-alones. In "The Visitor," father-son themes between Jake and Ben Sisko are explored in a novel way, utilizing time travel as Jake spends his life seeking to rectify an earlier accident. The episode, with its tantalizing hints of a possible future also underscores a bittersweet theme of letting one's life slip away while pursuing a potentially unachievable goal. "The Visitor" is often cited as one of the best hours of Trek ever.

Hippocratic Oath
This episode, while also moving forward the Dominion War arc, also tells a unique story that stands alone. The Jem'Hadar soldiers Bashir and O'Brien encounter aren't faceless, anonymous Jem'Hadar, but are depicted as individuals, seeing beyond simple good guys and bad guys. Their plight offers no easy solutions, and the conflict that arises between Bashir and O'Brien isn't a simple, cut-and-dry situation. The resolution of the situation satisfies neither the Doctor nor the Engineer, yet rings with painful truth.

Indiscretion
Throughout Season Four, characters we thought we knew are given more depth in believable ways, changing how we feel about them. Dukat, who began the series as a typical antagonist, finds his daughter and suddenly his character has history and emotions we didn't ever expect, challenging our assumptions. This three-dimensionality adds to the realistic moral ambiguity that marks DS9 as a critical success.

Little Green Men
In a wonderful distraction from the serious heaviness of much of Season Four, this episode is funny, irreverent and smart. "Little Green Men" takes a modern urban legend (the Roswell alien landing) and cleverly constructs a feasible DS9 story that dovetails with conspiracy theories of aliens landing in New Mexico in the late 1940's.

The Sword of Kahless
The episode stands alone as an adventuresome quest for a lost artifact, features the return of several familiar faces (Kor, Toral) and adds another facinating chapter to Klingon folklore. The theme of absolute power corrupting absolutely is well played out here, as well as the ultimate wisdom of the final decision about what to do with the Sword of Kahless.

Homefront
So far in Star Trek, we'd never seen the Federation in wartime. "Homefront" shows us 24th century Earth during a time of open hostilities and outlines what happens there. This episode explored some timeless themes of trust and citizen's rights during a time of war (more resonant now than ever), and introduced Joseph Sisko, father of Ben and grandfather to Jake.

Paradise Lost
The second part of a story began in "Homefront," this episode reveals that the paranoia and state of emergency on Earth was orchestrated not by the Dominion, but by Starfleet Admiral Leyton, proving that in times of uncertainty and insecurity, human beings aren't immune to wrongful actions in the pursuit of something right. Like other episodes this season, the lack of a simple, tied-up solution gives the series a deeper realism — illustrating universal truths about humanity (and all sentient races) without taking the easy way out.

Hard Time
In one of the harshest episodes of the season, O'Brien returns to daily life on Deep Space Nine after believing he spent 20 years in a prison. In his mind, those years moved no faster than real time, but in reality he now has to readjust to the life he'd left shortly before. Again, there was no magic wand at the end to wipe away his torment, only the moral that harsh things can happen to any individual, and that while loved ones and friends can help, it's up to that individual alone to pick up the pieces and move forward with life.