The X-Files "Ice" at 25: The episode that changed Mulder and Scully forever

When discussing the first season of The X-Files, or the show’s overall legacy, “Ice” deserves special praise. First aired 25 years ago on Nov. 5, 1993, the Season One is a bottle episode set on an remote research base in Alaska.
Borrowing liberally from John Carpenter’s The Thing, the eighth installment was the best of the series thus far, raising the bar for episodes to come. 
The alien parasite story is the third by renowned X-Files writers Glen Morgan and James Wong (after “Shadows” and “Squeeze”). More than previous episodes, “Ice” puts the agents’ trust in one another to the test. It aligns with the show’s overarching theme of paranoia but advances the Fox Mulder/Dana Scully dynamic, and places them in their most stressful context yet—while pushing personality differences to the extreme

The (literal) cold open introduces Arctic Ice Core Project, 250 miles north of the Arctic Circle. A dog walks through a base littered with dead bodies as a man begins a video transmission. “We’re not who we are,” he utters, hauntingly, before being attacked by another man—a confrontation that ends with both men turning guns on themselves.
After the opening credits, the agents watch an outpost transmission. The man who shot himself in the previous scene announces his team surpassed the previous record for drilling into an ice sheet, which, in true X-Files fashion, also happens to be in a meteor crater. The set-up echoes a classic sci-fi trope: There are some things man is not yet ready to know. 
From an airfield in Nome, Alaska, the duo meet the research team traveling with them to inspect the outpost: Dr. Hodge (The Walking Dead’s Xander Berkeley), Dr. Nancy Da Silva (Desperate Housewives’ Felicity Huffman), as well as Dr. Denny Murphy, and Bear the pilot. Da Silva and Hodge immediately offer a mirror image of Scully and Mulder. Writers Morgan and Wong lay the “trust no one” groundwork by having Hodge ask the FBI agents for identification. “We want to make sure we are who we say we are,” he says.
At the outpost, it appears the previous team killed one another, with the exception of the two who killed themselves. The same dog from the cold open bites Bear, who becomes increasingly violent. With the discovery a micro-organism has been living in the ice for a quarter of a million years, and is in the blood of the dead—and the dog—the team quarantines themselves.
Instead of going along with the test to check for infection, Bear attacks Mulder. They discover a wriggling object under his skin, extract a worm, and Bear swiftly dies.

Tensions rise in the claustrophobic setting. They discover the worm attacks the brain, causing aggressive behavior. So, are they exhausted and frightened in the cramped quarters, or is a little bugger pulling the strings? 
Mulder and Scully’s relationship is still young, and they clash on how to deal with the worm extracted from Bear. Scully wants to kill it to prevent outbreak; Mulder wants to preserve it. The writers highlight how dangerous Mulder’s quest for answers can be, larger consequences be damned. Meanwhile, Scully is a voice of reason, not a skeptic.

Mulder finds Murphy dead just as the team appears. Hodge accuses him of murder. Mulder doesn’t take this well, which leads to him and Scully pointing guns at one another. Classic Mulder! His obsession with proof (and being right) is a flaw as much as an attribute. Not to put too fine a point on it, this ain’t great for workplace relations, and Spooky Mulder is acting like a nutter butter. 
A round of “put it down!” and “you put it down first!” ensues. Mulder pleads with Scully: “For God’s sake, it’s me.” She replies: “Mulder, you may not be who you are.” Morgan and Wong bring us full circle to suspecting everyone is an infected “other.” He agrees to being locked up, with the ominous warning: “In here I’ll be safer than you.” 
Mulder is quick on the draw in this episode, and after he’s locked away, Scully is again the voice of reason. Hodge and Da Silva question her now being the only one with a gun, so she simply tosses it instead of escalating matters. 
Scully discovers two worms don’t play well together, and will kill each other in the same host body. If Mulder is infected, introducing a second worm into his body will cure him. If not, she’ll essentially be killing him -- and they only have two live worms.
This leads to consensual groping as both agents inspect one another for worms under their skin. “I don’t trust them; I want to trust you,” says Mulder. The scene highlights the growing bond between them; Morgan and Wong contrast it to the general mistrust between Hodge and Da Silva because Scully puts herself at risk by inspecting Mulder alone. 

With both agents cleared, suspicions turns to the other pair. Following a struggle, Hodge and Da Silva hold down Mulder to introduce a worm. At the last moment Hodge glimpses movement under Da Silva’s skin, revealing her to be the infected murderer. They restrain her, and introduce a second worm, ending her infection.
Back in Nome, Mulder wants to properly study the organism back at the site. Hodge informs him the outpost was torched, presumably by a government agency. 
“It’s still there, Scully. 200,000 years down, in the ice,” says Mulder.“Leave it there,”Scully insists.
And with that, “Ice” pushes The X-Files forward, and strengthens the Mulder/Scully relationship. Without relying on the suggestion of a shadowy government conspiracy, this early tale amps up the creeping paranoia that will continue to be a recurring motif. And the best part? Like the truth, the threat is still out there.