This weekend’s episode covered some new territory for the doctor. Clara and the doctor are dealing with a ghost. Exciting? I know! The episode starts off at an under water base with a crew of five. They have discovered some type of ship, which they have brought to their base. Of course, that’s their first mistake. Something goes wrong with the unknown ship and one of the crew members is killed. After he is killed the crew members, we see his ghost, who tries to attack them. They escape and quarantine themselves into an area where the ghost apparently can not enter.

Next thing we know the doctor and Clara arrive on the base. They have arrived on board not knowing what is happening or why they're there. However, the Tardis seems to be out of sorts so the doctor has to put on the emergency break in order to keep the Tardis from trying to leave the base. Clara and the doctor begin to look around when they are confronted by the ghost. Initially the ghost surprises them but curiosity gets the best of our friends. We follow the ghost and end up in the same room that the other crew members were in at the start of the episode. Once they get there, the ghost then tries to kill the doctor and Clara. They make a run for it and end up in the same quarantined room as the rest of the crew. Looking out from the inside, the doctor notices that the ghosts are moving their lips as if they're trying to communicate, but he can not make out what they are saying.

The crew begins to tell the doctor what has happened. After some back and forth banter, the ship goes into day mode. It is then revealed that the ghosts do not come out while the base is in day mode. The doctor appears to not be convinced that they're dealing with ghosts. Clara and the doctor begin to check out the ship and notice that a very powerful part of the ship is missing. When he brings this to the crew's attention, nobody seems to know where the part is. The doctor, after discussing it with himself first, exclaims that they are in fact ghosts. As usual he's very insensitive of the crew's feelings about their ghost friend. Clara reminds him to read some cards I'm sure she created in order to show some empathy from time to time. He reads off what's on the card and makes the situation just as awkward as before he read them. But of course true to form, the doctor continues talking. As he goes on something like a rant about the current situation, the ship goes back into night mode. This startles everyone. They know they need to get back to their quarantined area before the ghost appears. Unbeknownst to them, one of the crew members went outside of the base for a minute. When he returns, not knowing that the base is in day mode, the ghost drowns him. He appears in a room with Clara and one of the other crew members. It takes them seeing his dead body floating outside to realize that he is a ghost. Before he can attack them with a chair another crew member gets the base back in day mode, causing him to vanish.

Now that the crew is another friend down, the captain tells them they must abort the base. When they call in the rescue personnel, the person who answers informs them that they are already on their way. When asked who contacted them in the first place, he explains that they received a call for help in Morse code. The doctor takes the phone and sends the rescue back, declaring that the base is under quarantine. It is clear that it is time to come up with a plan. The doctor decides to put the ship back in night mode in order to talk to the ghost. He feels that this is the best way to get answers as to what the ghost wants. They set up a plan in which they trap the ghost in the same room they were quarantined to in the beginning of the episode. The doctor decides to enter the room with them and have a chat. The captain figures out what they are saying over and over again; ‘the dark, the sword, the forsaken, the temple.' After figuring out what the ghost is repeating, the doctor translates what it really means. It actually represents coordinates. They figure out that the ghost is apparently killing people in order to use their souls as some kind of transmitting device. The more people die, the stronger the signal.

Right when they figure this out the base begins to flood, thanks to the ghost messing with the controls. As everyone runs for the Tardis Clara, the Captain and another crew member are separated from everyone else. The doctor tells Clara that he’s going back in time to figure out the cause of this whole situation so he can save her. She reluctantly agrees to be left behind and off he goes. Clara and the other two are trying to relax in one of the rooms when they notice something floating outside in the water. As it gets closer it appears to be a ghost. Clara is horrified when she notices who it is.  I'ts the doctor. And of course the episode ends right there. I'm sure the doctor has something up his sleeve. He is in no way actually dead... Right?

Tune in next Saturday for the conclusion of this episode of this episode.