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The Power of Three

The Power of Three was the fourth episode of the seventh series of Doctor Who produced by BBC Wales. It contained the reappearances of Brian Williams and UNIT. Kate Stewart, daughter of the Brigadier, made her first appearance in a piece of BBC-produced television.

The final scene of the episode, in which the Eleventh Doctor, Amy and Rory enter the TARDIS was the last regular scene filmed with Karen Gillan and Arthur Darvill in their roles.


In July, Amy and Rory return home after a trip with the Eleventh Doctor. They have been gone long enough that much of the food in their refrigerator has spoiled, their dirty laundry is pungent, and 59 messages have accumulated in their answering machine. After realizing that they lead two lives, their life with the Doctor and their everyday life, Amy and Rory conclude that they should choose one to stick with; but then are whisked away on another adventure with the Doctor. After returning home, the couple settle back into routine.

d62Life with the Doctor is mad and wonderful because there’s always something interesting around the corner; every day life on Earth is, well, rather dull, predictable and uninteresting. Every time that Amy and Rory go away with the Doctor, they become a part of his life; however, he has never stuck around long enough to become a part of theirs; until now.

As Amy and Rory sleep, a mysterious black cube materialises in their room. They’re awoken the next morning by Rory’s father, Brian, who gets them to notice that many black cubes are filling the streets. They go outside and find the Doctor examining a cube in the park right across the street; “Invasion of the small cubes. Got to admit, didn’t see that one coming.” Several news reports show that the cubes are all over the world, and every specialist in the unusual and alien are trying to figure out what the cubes are. Some speculate that this could be the most clever marketing campaign ever.

In the meantime, the Doctor and his family examine the cubes in the TARDIS, which he has moved into Amy and Rory’s flat. Brian makes several possible guesses as to what the cubes could be, such as spaceships, bombs, hard drives, and pieces of a puzzle; impressed, the Doctor congratulates Brian on his theories. Instructing Brian to watch the cubes for any activity, the Doctor takes some equipment from the TARDIS, planning to turn the Ponds’ kitchen into a makeshift lab. Rory goes to dress for work, surprising the Doctor. Amy asks what he thinks they’re doing when not travelling with him; the Doctor retorts, “mostly kissing, I guess”. Setting up his equipment, the Doctor learns Amy now writes for a travel magazine, having given up her modelling job, and that Rory works part-time at a hospital.

As they continue talking, a UNIT strike team breaks into the flat, bringing a trouser-less Rory into the kitchen with them. Amy jokes about being envious of Rory’s situation. A woman named Kate Stewart walks in and apologizes for the rudeness of the UNIT soldiers. She uses a device to X-ray the Doctor and confirm his identity; from UNIT’s reports, the Doctor has two hearts and has a strange dress sense. Kate goes on to explain that a spike in artron energy tipped them off to his presence. They need the Doctor’s expertise to deal with alien threats they haven’t dealt with. She continues, saying that they’ve tried destroying the cubes by several means; the cubes survived plus and minus 200 Celsius, simulated five miles of water depth, being dropped out of a helicopter at 10,000 feet, and being rolled over by their best tank. The Doctor decides that the best thing to do is observe the cubes.

After UNIT departs, the Doctor watches the cubes with Amy and Rory, but quickly becomes bored. Needing to be constantly busy or risk the loss of his sanity, the Doctor performs several different tasks; he paints the Ponds’ fence, practices with a football, and vacuums their flat. Seeing that it only took him an hour to do these things, the Doctor prepares to go off and have a few adventures to restore his sanity. Finding Brian hasn’t moved since he ordered him to watch the cubes, the Doctor instructs him along with Amy and Rory to continue monitoring them; if they need him, they know his phone number. He also reassures them, by explaining the TARDIS will have access to all news channels in this time period as well.

As time goes on, Amy and Rory live their normal lives, taking on commitments. In October, Amy promises to be a bridesmaid at her friend Laura’s future wedding, while Rory agrees to work full time at the hospital. Both tell each other what they did, finding it a bit odd as they’re so used to travelling with the Doctor. In the meantime, Brian has been keeping a log; he watches the cube when he’s awake and records it when he’s asleep. Rory mocks him for near-religiously following the Doctor’s orders, but Brian remains adamant and continues his log. At this time, the cubes have become part of every day life, being used for multiple different tasks.

During December, Rory deals with a repeat patient while a small girl appears to be possessed by her cube. An old man is in his room, waiting to be given his medication and discharged as an orderly enters, asking if he needs anything. He says no as a second enters; the old man asks this orderly to have the other leave. Despite his protests that he doesn’t need help, the orderlies try subduing him. In the middle of his struggle, he removes one of their masks, revealing their inhuman nature. As the old man screams, the little girl (who had also entered the room) looks on with an expressionless face.

During the Ponds’ anniversary, 26 June Amy phones the Doctor, wondering where he is. He arrives with a bouquet just as she finishes her call. He takes Amy and Rory with him to the Savoy Hotel’s opening night in 1890 as his anniversary gift to them. However, despite his promise that nothing would go wrong, they ended up having to stop Zygons, who had replaced half the staff, from trying to remove their spaceship from underneath the hotel. They continued to go on several trips, during which Amy accidentally married Henry VIII.

Eventually, the Doctor takes them back home to finish their anniversary with friends and family. Brian, noticing that Amy and Rory are wearing different clothes from before they left with the Doctor, asks him how long they’ve been gone. Explaining that it’s been seven weeks, the Doctor is asked what happened to all his previouscompanions. With a look of regret, the Doctor explains that some of them have left willingly or he purposely left them behind, and very few have died. However, he promises Brian that he will do everything he can to make sure Amy and Rory don’t die while travelling with him. Admitting to Amy that he misses them, the Doctor asks if he can stay with her and Rory.

During July, exactly one year after the cubes appeared, Brian prepares to take a nap while his camera records for him; the cube spins slightly after he closes his eyes. Noticing this, he tricks it into thinking he’s asleep, catching it spinning. At the Ponds’ flat, Rory sees a cube open on the side opposite of him. He tries to see what’s inside of it, only to have the device toy with him and open on sides he can’t see. Amy sees one glow and touches it, only for it to prick her hand with needles and take her pulse. Playing a tennis game on the Ponds’ Wii, the Doctor sees a cube float in front of the screen; he dismisses it at first, but realizes the severity of what’s happening. He threatens that if the ones who created it wish to harm humanity, he will defend them to his last breath; it fires a laser, forcing him to flee into the hall.

Brian arrives just as everyone meets and talks over each about what their cubes are doing. The Doctor looks back to see that his cube surfed the web and that there are news reports saying that some of the cubes have caused injuries all around the world. Rory is called in to assist with those injured in the area; Brian goes with to offer any assistance he can. The Doctor discovers a message on his psychic paper, telling him to go to the Tower of London, which houses one of UNIT’s bases. Kate explains that several of the cubes captured by them each display only one unique function; some harmful ones are spewing fire or causing mood swings, while the harmless ones do things such as playing the “Chicken Dance” in an endless loop. He sets a computer to look for the source of the signal activating the cubes.

Noticing that Kate is beginning to panic, the Doctor tells her not to despair as her dad didn’t. Kate is left shocked as how the Doctor figured out her identity; she’s the daughter of his old friend, the Brigadier. He questions her as to why she dropped “Lethbridge” from her name, learning she did so to not get any favors from those in UNIT who knew the Brig. Kate explains that her dad taught her everything he could and that, in the words of his old friend, “Science will lead,” explaining why she took the position of Head of Scientific Research. The Doctor smiles. Suddenly, the cubes become inactive after 47 minutes. The Doctor is left confused and goes outside, complaining about the lack of ventilation underground bases have.

At the hospital, Rory sends Brian to retrieve some medical supplies he needs to treat patients. Not knowing where the supplies are, Brian asks the two “orderlies” for some help. However, they ingore him. Brian continues to ask for help, seemingly annoying them as they turn around with sedatives in hand. Brian is left shocked.

Outside the Tower, the Doctor and Amy debate the merit of travelling the way they do; Amy considers it “running away” and the Doctor considers it “running to”; he travels to see whatever the universe holds before it’s gone forever. During their conversation, the Doctor realizes the cubes acted out to gain attention and scan the entire planet. The power at UNIT goes out, and the cubes start a countdown from seven. At zero, the cubes open but contain nothing. Moments pass when around the world, people start going into cardiac arrest with the Doctor experiencing heart failure with one heart. The program he set earlier to find the source of the cubes comes up on the screen, revealing seven different sources; the nearest being the hospital where Rory works. He and Amy leave for the hospital.

At the hospital, Rory is searching for Brian. Seeing him being wheeled into an out-of-order lift by the false orderlies, Rory follows only to find it empty. Touching the wall in the lift, Rory finds it now houses a portal; it takes him to an alien ship, which houses patients that have been kidnapped over the entire year. The two orderlies close in on him with sedatives.

The Doctor and Amy arrive at the hospital, looking for both Rory and Brian along with the source of the cubes’ signal. He discovers the little girl with the active cube and reveals her to be a simple android overseeing the entire operation. The Doctor shuts her down with the sonic screwdriver, but collapses in pain as one heart is not enough to keep him alive. Amy quickly grabs a defibrillator and, despite his protests, manages to restart the Doctor’s other heart. The Doctor dances with joy, thanking Amy; however, he then orders her to “never do that again.”

Tracing the signal, they discover the same out-of-order lift and use the portal it to reach the alien ship. The Doctor explains that the ship exists outside of the universe, and they traveled through a wormhole. They find Rory unconscious and quickly wake him. The Doctor disables the orderlies while ordering Amy and Rory to return everyone that was kidnapped through the portal. The Doctor examines the monitors, discovering that seven ships are using seven portals to reach earth. A humanoid appears on the other side of the monitors.

Amy and Rory return, confused by the sight of him. The Doctor explains it’s one of the Shakri, whom are told of in Gallifreyan legends as, in the Doctor’s opinion, the “pest controllers of the universe”. The Shakri consider humanity to be a plague that must not spread, hence why they’ve chosen to start killing them; the blackouts were caused by the cubes sucking up electricity to exterminate 1/3 of humanity. The Doctor says that humans have done more good than harm, and he is willing to defend them regardless of what the Shakri believe.

With a smug smile, the humanoid announces a second wave of cubes will be soon unleashed on Earth, before vanishing. Amy is left confused as to what happened. The Doctor explains it was simply a hologram produced by the ship; similar to an “interactive propaganda poster”. Fiddling with the controls, the Doctor takes control of the cubes already on Earth; he manages to reverse the damage done by the cubes, restarting the hearts of everyone killed by the Shakri. However, as a downside, this task has created a backlash of energy that will blow up the ship. The Doctor, Amy and Rory flee to the portal, barely managing to get back to the hospital.

After having dinner with Amy, Rory and Brian, the Doctor prepares to take off for solo adventures again. However, Brian encourages Amy and Rory to return to being the Doctor’s full-time companions; travelling with the Doctor gives them the chance to save the world and make it better. The Doctor agrees, even offering Brian a place in the TARDIS. However, Brian turns down the generous offer, saying that someone has to stay behind and water the plants. The Doctor and the Ponds board the TARDIS and shut the door.

Amy narrates, saying “So that was the year of the slow invasion, when the Earth got cubed, and the Doctor came to stay. It was also when we realized something the Shakri never understood. What cubed actually means. The power of three.”


The Eleventh Doctor
Amy Pond
Rory Williams
Kate Stewart
Brian Williams