Doctor Who’s Best Cosmic Horror Episode Is More Than “Event Horizon For Kids”
Yes, we’re making that comparison.

A spaceship in deep, deep space. A crew plagued by horrific visions preying on their worst fears. An ancient, malevolent force that threatens to break out of its prison, and brutally slaughter anyone standing in its way. It’s the ominous and grim premise that turned Paul W.S. Anderson’s 1997 sci-fi horror Event Horizon into a cult classic, and which spawned many copycats and homages. And one of those from a TV show you’d least expect to do a riff on a Paul W.S. Anderson gorefest: the Doctor Who Season 2 episodes “The Impossible Planet/The Satan Pit.”
In “The Impossible Planet” and “The Satan Pit,” which aired on June 3 and June 10, 2006, respectively, the Doctor (David Tennant) and Rose Tyler (Billie Piper) land on a sanctuary base for deep space expeditions. But this isn’t just deep space — they’re at a far-off corner of the universe that houses no other life for thousands of miles. And this isn’t just any old sanctuary base — it’s on an unnamed planet that is impossibly orbiting a black hole. But things only get stranger from there: as the two explore, they find writing on the wall saying “Welcome to Hell,” along with ancient, untranslatable characters. It turns out the skeleton crew on the base arrived there because of the impossible existence of this planet — some great energy source is generating a gravity funnel that keeps it from being sucked into the planet, and that allowed them to fly safely in. They’ve been drilling for miles into the planet to find the source of this energy, and they’ve finally almost reached it. But then, that’s where things take a turn for the worse.
First come the ominous messages that appear as malfunctions in the Ood, the squid-like slave race that serves humanity, and in the space base itself. “The Beast and his Armies shall rise from the Pit to make war against God,” one Ood politely says to a startled Rose. And then there’s the repeated phrase that the base’s computer, Rose’s phone, and the Ood keep repeating: “He is awake.” As the Doctor, Rose, and the crew grow increasingly uneasy over these strange malfunctions, one of the crewmembers, Toby (Will Thorp), starts to hear the voice of this nameless Beast, before getting possessed by it. He passes his possession onto the Ood, who start to attack the humans. From there, the crew members get picked off one by one, while the Doctor and Science Officer Ida (Claire Rushbrook) descend into the Pit to discover its secrets.
Yes, this two-parter — especially the first part, “The Impossible Planet” — is effectively “Event Horizon for kids,” right down to the eerie set-up and the dashes of eldritch horror. While the episodes naturally shy away from the excessive eye-gouging and extreme bloodshed that characterized Anderson’s movie, like Event Horizon, it feels like the best kind of low-budget riff on Lovecraftian horror. It’s no coincidence that the show designed the Ood to look like Cthulhu, or that the crew frequently references going mad at the sight of the black hole.
Cthulu, is that you?
But the thing that makes “The Impossible Planet/The Satan Pit” stand apart from all the other copycats is that it takes things beyond the “creepy demonic thing slaughters everyone” premise. First, it avoids the B-movie-meets-exploitation-horror edge of Event Horizon (because there’s no way Doctor Who would go there anyway), even though there’s a charmingly grimy industrial look to the whole episode. Instead, Doctor Who smartly embraces the religious horror aspect of the story, centering most of the second half, “The Satan Pit,” on a quiet conversation between the Doctor and Ida as they muse over the nature of religion and the existence of the Devil. The science-minded Doctor rejects the idea of an ancient evil behind every single religious myth, while Ida wonders if evil is simply “the things men do.” It’s the kind of conversation that would feel out of place in Event Horizon and its many ripoffs. The episode does deliver its fair share of action-packed beats, as the crew on the base attempt to escape the Ood, but it’s this conversation that makes you wish Doctor Who would attempt more religious horror, if only to get more philosophical musings like this (and, of course, creepy demonic dread).
In the end, comparing this two-parter to Event Horizon may actually do it a disservice; its similarities are mostly surface-level, while the extreme gore and edgy shocks of brutality of Event Horizon has caused the film to develop a distasteful reputation that Doctor Who probably wouldn't want to be associated with. While it’s a fun, cheeky comparison to make, “The Impossible Planet/The Satan Pit” is ultimately just a really solid cosmic horror episode that shows just how versatile the show can be.