Dark Water was the eleventh episode of the eighth series of Doctor Who produced by BBC Wales. It saw the return of the Cybermen and the Master, and the Twelfth Doctor’s first encounter with both. The events of the episode centered around the sudden and unexpected physical death of Danny Pinkafter a fatal accident, his transition into an existence beyond his body and the effect his bodily demise had on Clara Oswald. The story also explored the concept of an engineered afterlife, and revealed the identity of the victim unintentionally murdered by Danny when he was still a soldier.
Dark Water showed an important aspect of the Time Lord’s regeneration process that had been mentioned before, but never seen before on screen: the possibility for a change of gender to occur. Missy, a mysterious figure throughout the series, was revealed to be the first female incarnation of the Master, showing for the first time in the history of the series a Time Lord, who had been portrayed by male actors, now being portrayed by a female actor.
This was also the first encounter between the Doctor and the Master since The End of Time, before they regenerated into their next incarnations, though while the cause of the Tenth Doctor’s regeneration was shown, it’s not revealed in Dark Water or Death in Heaven when the previously male Master had regenerated, nor how she had escaped the pocket dimension that held Gallifrey.
Clara is ready to confess to Danny the adventures she’s been having with the Doctor, despite telling him she wasn’t. She’s about to tell him over the phone, when Danny steps out into the road and is killed by an oncoming car. Unable to deal with her grief, Clara calls the Doctor for help with the intention that he’ll change events.
The Doctor picks up Clara asking her where she wants to go, almost immediately sensing something is wrong. She asks the Doctor to take her to a volcano, all while collecting up theTARDIS keys that are hidden in the console room. After the Doctor sets the destination, Clara uses a sleep patch on him.
The Doctor seemingly wakes on a volcanic planet, and Clara tells him what’s happened and that she is holding the seven TARDIS keys hostage. Clara then reveals that she knows lava can destroy them and if the Doctor doesn’t let her try to save Danny she’ll throw them all into the crater in order to prevent the Doctor from ever re-entering the TARDIS, proving that she’s serious by throwing one straight away. The Doctor point-blank refuses to save Danny since his death is part of her personal timeline, trying to take control of the situation by telling her to throw another key in the lava. Clara then throws all but one in, and when the Doctor still won’t help she throws the last in before suddenly being overcome by the enormity of what she’s done. The Doctor then reveals that she didn’t actually knock him to sleep (the two are still in the console room), and this has been a telepathic test to see how far she’d be willing to go to be with Danny again. Seeing the extremity of her desire to see him, the Doctor agrees to do everything he can and connects her to the TARDIS’ telepathic circuits, as her time stream’s connected to Danny’s. The TARDIS takes them to wherever she thinks Danny now is.
Danny wakes-up in the Nethersphere, and is greeted by Seb, who informs him of his death.
The TARDIS has taken the Doctor and Clara to the 3W, where they see skeletons seated in watery graves. They’re greeted by Missy. Stating that he clearly didn’t receive the formal advance materials, she kisses the Doctor, and claims to be a Mobile Intelligence Systems Interface. Missy lets the Doctor feel her heart, evoking a reaction of quiet surprise from the Doctor.
In the Nethersphere, Seb asks Danny if he’s ever killed someone, due to a request from someone Danny could have killed in the army. Remembering his “bad day”, the child Danny accidentally killed is revealed to him.
Chang reveals the dark water to the Doctor and Clara. When submerged, only organic matter can be seen – the skeletons are inside something else, hidden by the water.
Danny meets with the child, who runs away when Danny tries reaching out to him. He and Seb hear a man screaming, which Seb explains to mean he left his body to science.
Chang then explains to the Doctor and Clara that the 3W was established after a discovery from television static, that their founder, Dr Skarosa, translated to be distant voices. Believing them to be the voices of the dead, Skarosa isolated some of them. Chang plays a recording of the voice that inspired 3W’s founding: “Don’t cremate me”. Chang tells them the dead are still conscious, and aware of everything that happens to their body.
Seb is explaining the same to Danny, who constantly feels cold because he’s still connected to his body, which is being kept in a cold place.
The Doctor states that the dead don’t come back, and Chang establishes a communication signal to the Nethersphere, and Clara is able to speak to Danny, with Seb’s assistance. The Doctor tells to Clara to ask Danny questions only to which would he know the answer.
Missy activates the tanks, and the skeletons stand. When Chang and the Doctor arrive, Missy reveals she was only pretending to be an android, and kills Chang. As the tanks begin to empty, the Cybermen are slowly revealed.
Clara asks Danny to name the restaurant of their first date – he can’t remember.
Missy shows the Doctor the Nethersphere, which is a Matrix data slice housing minds of the deceased in edited forms, while their bodies are used for Cyber-conversion. The Doctor knows the Nethersphere (actually a small sphere within 3W) which is containing the neural patterns is actually Gallifreyan technology, and Missy reveals that she is indeed a Time Lord, or rather a Time Lady as she prefers to be called. The Doctor asks her which Time Lady she is – she’s the one he “left for dead”, without expecting her to “find her way back”. The Doctor runs out of the 3W, which is St Paul’s Cathedral.
Clara asks Danny more information about her and tells him that if he is Danny, she is determined to find him in the netherworld and threatens to hang up if he says “I love you” one more time instead of answering her questions. Danny tells Clara she must continue her life and not follow him; he repeats the same words for the last time and she disconnects the communication signal. Seb gives Danny the option to delete himself, which would relieve him from the surge of emotional trauma from his call with Clara.
Back in 3W, Clara turns around to see a fully-revealed Cyberman in the water tank. The Cybermen activate, and begin marching down the steps of St Paul’s Cathedral. The Doctor yells at civilians to run away, but he’s dismissed as an angry Scotsman. The Doctor demands that Missy tell him who she truly is, and Missy reveals that her name is short for “Mistress” as she couldn’t keep calling herself by her previous title… the Master. The Doctor initially reacts with disbelief that quickly turns to horror when he realises she is telling the truth and his old nemesis has returned. In the Nethersphere, Danny is on the verge of disconnecting himself, and sees the child he killed reflected on the screen of the iPad he holds.