The Doctor and Clara investigate a spooky underwater base where the dead won’t stay dead — and where every corridor seems designed for maximum jump scares.
Short Synopsis
The Doctor and Clara arrive at an underwater mining facility in the 22nd century. The crew is being stalked by ghosts — yes, actual ghosts — who turn out to be broadcasting coordinates for an alien spacecraft. Naturally, the Doctor decides to investigate the mystery instead of running away, because “RUN AWAY” is not in his vocabulary.
Extended Storyline
We splash down (sorry) into Caithness, Scotland, now buried under a reservoir, where a mining crew has just uncovered an alien spacecraft. Bad news: it came with a couple of very angry ghosts. And unlike most ghosts, these ones don’t just go “boo.” They carry weapons, look terrifyingly soggy, and occasionally try to kill you with whatever’s lying around.
The Doctor and Clara arrive to find the surviving crew already frazzled. There’s Cass, the deaf-but-decidedly-in-charge leader, her translator Lunn, corporate suck-up Pritchard (boo, hiss), and a few other employees who clearly didn’t sign up for the “get murdered by aquatic phantoms” clause in their contracts.
The base is designed with a “day” mode and a “night” mode, because apparently nothing says “safe working environment” like switching off most of the lights while ghosts are roaming. Unsurprisingly, the ghosts are more active in the dark. (Rule one of horror stories: stop installing creepy dimming switches.)
The Doctor, naturally, is over the moon. “Real ghosts!” he declares, practically bouncing with glee. Clara, meanwhile, is quietly taking notes on how her Time Lord friend seems more excited about specters than is probably healthy.
But as the Doctor investigates, the mystery deepens. The “ghosts” aren’t just wandering aimlessly — they’re repeating patterns, luring people to the spaceship, and even trying to tamper with the base’s systems. The Doctor realizes they’re transmitting coordinates, like spectral Wi-Fi signals: directions to something hidden in the spacecraft.
We also meet the Fisher King — or at least the legend of him. A towering alien warlord who apparently used the ship as bait, marking his victims with strange alien runes. Anyone who reads those markings (and of course someone does) becomes a transmitter upon death, rising again as a ghost to pass on the coordinates. It’s the universe’s worst chain letter: read the message, die, and then haunt your coworkers.
Naturally, Pritchard — the greedy corporate rep — is the first to get himself killed. His ghost immediately joins the parade of the damned. The Doctor is equal parts horrified and delighted, because nothing says “mystery worth solving” like a growing pile of corpses.
By the end of the episode, things have gone full horror-movie: ghosts hunting through corridors, crew members panicking, and the Doctor setting up experiments to test their behavior. In a final, chilling reveal, the Doctor looks out into the water… and sees his own ghost floating there, silently mouthing words.
Cliffhanger: The Doctor is destined to die here. And the audience collectively yells, “Well, that escalated quickly.”