Series 8 premiered in August 2014, a year after Peter Capaldi was announced as the next Doctor. The main arc revolved around a mysterious woman who called herself Missy. She would greet people who recently died and welcome them to “paradise” or “the Nethersphere.” Throughout the series Doctor Who fans speculated about her identity. Some thought it was another incarnation of River Song, since she called the Doctor her boyfriend. Others thought she was the Rani, a villain who appeared during the Sixth and Seventh Doctors’ eras.
“Dark Water” and “Death in Heaven” serve as the finale to series 8. Clara begs the Doctor to save Danny Pink, who was killed in a traffic accident. He agrees, even after it appears Clara destroyed the TARDIS keys. They use the telepathic circuits to track Danny, and land at 3W, a mausoleum that takes special care of the deceased. Missy introduces herself to the Doctor with a deep kiss, unsettling him. She poses as an android to further the deception.
Clara manages to have a conversation with Danny in the Nethersphere, but the Doctor has some serious doubts. 3W is operating under the assumption that the dead remain conscious which he rejects outright. He’s distracted by the puzzle and misses the reveal of the Cybermen, who have been hiding in plain sight as the skeletons. They march out onto the steps of Saint Paul’s Cathedral, mirroring a shot from the Second Doctor’s story The Invasion. The Twelfth Doctor frantically tries to warn people but is ignored. To rub it in, Missy finally reveals herself as The Master.
Kate Stewart, Osgood, and UNIT show up and capture Missy. The Cybermen mysteriously fly up into the sky. One self-destructs over London while the rest fly off. Before the Doctor can get Missy to reveal her plans, both Time Lords are shot with tranquilizer darts. Later, onboard UNIT’s plane, Missy taunts the Doctor with knowing the location of Gallifrey but refuses to tell him. She also shoots Osgood for no good reason. The Cybermen intercept the plane and rip out a piece of the fuselage. Kate and the Doctor are sucked out. The Time Lord is able to get the TARDIS to catch him while the fate of Kate is unknown.
Clara has been surrounded by Cybermen, trapped in Saint Paul’s. One of them knocks her out and brings her to a graveyard. He reveals himself as Danny, to Clara’s horror. The Doctor joins Clara and Danny and asks him for help figuring out Missy’s plans. Danny reveals that more Cyber Pollen will rain down to convert the living into Cybermen. Missy appears and gives the Doctor control of the Cyber army as a present. She just wants her friend back. Maybe if she proves they’re more alike than the Doctor realizes, he’ll be her friend again.
But the Doctor doesn’t rise to Missy’s bait. He refuses to take control of the Cyberman army. Instead he declares himself an idiot with a box who’s just passing through and helping out. He gives control of the Cyber Army to Danny, who instructs the army to fly into the clouds and destroy them. Clara wants to shoot Missy in revenge but the Doctor steps in to shoot his friend himself. However one last Cyberman vaporises Missy before the Time Lord gets a chance. After discovering Kate Stewart unconscious but alive, The Doctor deduces the Cyberman must be the Brigadier, her father.
“Dark Water” and “Death in Heaven” are a great series finale. Having the Master return as Missy after a five-year absence was a great idea. Michelle Gomez steals all her scenes. But having the Brigadier appear as a Cyberman was a controversial choice. The actor who played him, Nicholas Courtney, died before his character could return to Doctor Who. During “The Wedding of River Song” there was a tribute to him as the Eleventh Doctor learns that the Brigadier has passed away. Three years later, Steven Moffat made a Cyber Brigadier essential to the plot of “Death in Heaven” by saving Kate and killing Missy. It just doesn’t work as well as the first tribute.