Arriving in the year 2119, The Doctor and Clara find themselves on an underwater, oil mining base where the crew have acquired something extraterrestrial and beyond their understanding. When murderous apparitions begin appearing throughout the base, the secret they hold might be the key to survival.
SPOILERS AHEAD!
Under the Lake opens with "The Drum", an underwater Scottish mining facility in the year 2119. On a routine expedition, the crew have uncovered what appears to be an alien craft buried within the rubble on the sea floor. While the crew are searching the vessel, strange happenings start unfolding almost immediately, namely the appearance of a top hat wearing ghost! One of the crew members being ambushed by the ghost stumbles backwards and accidentally sets off one of the thrusters, immolating Commander Moran in the process. Upon making their escape, the crew encounter the top hat ghost once more, but this time with the empty-eyed specter of Moran in tow. Its very rare that The Doctor will face a classic monster archetype like vampires, zombies, or even ghosts, but when he does, most of the fun comes from knowing that they can't possibly be what they appear to be and that there is an alien origin explanation for it every time.
The Doctor and Clara finally arrive three days after the attack to a dark and seemingly abandoned base. They follow a trail of obvious signs of panic and struggle, until they encounter a pair of translucent, eye-less, intangible men, which inexplicably lead them to the alien ship resting comfortably in the cargo bay. Once the "ghosts" finally decide to arm themselves and attack, they narrowly escape, only to run into the bewildered crew of the Drum, who proceed to tell them they're being hunted by the same creatures, one of which resembles their deceased commander. One thing out of the norm for this story was The Doctor actually drawing the conclusion that what they were facing had no secondary explanation. These were, in fact, ghosts. It would seem that whatever alien energy brought on by the mysterious spaceship is able to harness the dead for its own means.
Doing what The Doctor does best, he decides to trap the ghosts and stick his face right in their business. The entire time, they've definitely been mouthing words, but no one has been able to hear them and they were thought to be random at best. Upon careful examination by the deaf crew member, Cass, she can read the words as follows, "the dark, the sword, the forsaken, the temple". As it turns out, the words are a cryptic version of star coordinates between Earth and an unknown point of origin. The Doctor has no choice, but to find the missing pilot. He then makes the decision to go back in the TARDIS to the time of the crash, before the region they're in was underwater and uncover the truth. Mere moments after his departure, Clara and the other crew members left behind spot a new ghost in the water, just outside the window. As it moves closer, she recognizes the chilling, gray-haired image of The Doctor's ghost!
Doctor Who has a history of two part episodes that don't come to fruition until the conclusion of the second half. While Under the Lake wasn't necessarily a bad episode, it feels as though most of the excitement will be showcased in the conclusion next week. The majority of the episode was spent running from ghosts, then escaping to a room to argue what the ghosts might want, which happened on at least three different occasions. Despite the inherent danger from the number of casualties, most of the story was dull and flat, never really explaining much and only picking up when the ghosts are active. It was pretty clear they were just trying to stretch the story to accommodate the experimental, consecutive two-parter run of this season. One can only hope that this isn't the formula the rest of the season will follow or we might be getting half a season of exciting thrills, and half a season of boring, thinly spread exposition.
