The last two episodes of The X-Files, “3” and “One Breath” were both quite anomalous, dealing as they did with Scully’s abduction and near death. “Firewalker” marks the end of this mini-cycle that began with “Ascension” by descending deep into the earth and returning Scully to the normal rhythm of the series, while postponing any immediate discussion of her experiences. She may have barely awoken from her coma at the end of “One Breath” but she’s back in the field now and that evocative ellipsis lends the episode a greater pregnancy and a peculiar comfort. Critics note that “Firewalker” was quite derivative, both of the classic episode “Ice” and Ridley Scott’s Alien but that seems intentional, as the point of the episode is partly to reinstate a classic X-Files model that we haven’t really seen since the end of the first season – Mulder and Scully working together with full FBI approval.

For that reason, “Firewalker” also marks a return to the classic crystalline style of the series, along with its muse – the cosmic forests of the Pacific Northwest, here presented as the enormous misty swathe of redwoods that surround a remote observatory that has mysteriously gone off grid. The opening credits roll over a magisterial sequence in which Mulder and Scully fly into this rugged region of Cascadia, signalling a much more atmospheric vision of nature than we find in “Ice.”

Nevertheless, with Scully back at the helm, the focus quickly shifts to inner space. For it turns out the object of paranormal enquiry here is the Firewalker, a remotely controlled volcanic exploration device that has picked up images of a human figure deep in the earth’s core. As occurs in “Little Green Men,” the opening episode of the second series, “Firewalker” insists on the analogy between inner and outer space, with one of the surviving scientists noting that the volcanic project is “a human endeavour even more important than man’s exploration of space.” In a fusion of physical and digital topography, the Firewalker sends back glitchy footage from deep in the earth’s core, evocative static spewed up by the volcano the scientists are investigating. It reminded me of the mysterious death of Rey Rivera a decade later – or, rather, the note that Rivera left behind. Taped to the back of his desktop computer, like an alternative modem, was a sprawling hypertexted letter that started: “Brothers and Sisters, Right now, around the world, volcanoes are erupting. What an awesome sight.”

There’s also a fascination here with being present at the inception of a viral global event. Interestingly, there are a few episodes in this series that suggest this event might take the form of a deadly fungus, in a flashforward to The Last of Us. The creature that the Firewalker detects is in effect a reimagination of H.R. Giger’s xenomorph as a fungus, causing spore panic and mycological horror. At the same time, this fungal threat, and the rhizomatic connections that come with it, links up with cutting-edge technologies in unsettling ways. At this moment in the 90s, silicon was a synecdoche for the cyborg future, from breast implants to computer chips, and the agents devote a fair amount of time to discussing the possibility of “silicon-based life forms in the deep biosphere,” one of the “Holy Grails” of geobiological research.

While “Firewalker” is largely a classicist episode devoted to “resetting” Mulder and Scully’s investigative rapport there is still a bit of a shift in the tenor of the ending post-Scully’s abduction. As always the narrative core remains open-ended but there is a more oppressive awareness of government containment now. The agents are whisked into quarantine, the army comes in to seal off the volcano, and the camera lingers on the badges of the biohazard unit, accompanied by ominous synth tones. The government – or “government” – are starting to feel more prominent then as agents of narrative containment, seeking to close down at every opportunity the open-endedness that is the core of the series’ aesthetic and ideological mission.