The Shakri are aliens that serve the Tally and they want to rid the Earth of the human contagion. The Shakri sends millions of cubes across the Earth which remain inert until activation. Once they activate, the cubes begin killing humans by causing heart attacks. Thankfully, the Eleventh Doctor, U.N.I.T, Amy, Rory and Rory’s dad Brian were able to defeat the Shakri and turn the human hearts back on again.

The Power of Three

★★☆☆☆

TX: 22/09/2012

Written by Chris Chibnall    Directed by Douglas Mackinnon

Amy and Rory decide that they need to spend more time on Earth with Rory’s dad Brian. It soon becomes clear to the Ponds that their lives are complicated as a result of time travelling with the Doctor. But at the same time, they don’t want to give up travelling with him. However, one day millions of small cubes appear across the Earth. U.N.I.T enlists the help of the Doctor, Amy, Rory and Brian. The Doctor meets Kate Stewart, head of U.N.I.T, who is the daughter of the late Brigadier Lethbridge-Stewart (Downtime). The Doctor realises that source of the cubes is linked to the hospital where Rory works at. One day, the cubes activate and start killing people through cardiac arrests. The Doctor, Amy and Rory rescue Brian who has been kidnapped by aliens that have infiltrated the hospital. The Doctor confronts the Shakri, who are behind the cubes. The Shakri are servants to the Tally and they have decided that the human contagion on Earth must be eliminated. The Doctor uses his sonic screwdriver to turn all the humans hearts back on. The ending of this episode is ruined by this deus ex machina, which author Terry Pratchett complained about seeing too many times in Doctor Who. The Doctor, Amy and Rory escape back to the hospital through the teleport link moments before the Shakri ship explodes. Back at home, Rory and Amy decide to continue travelling with the Doctor, however Brian decides to stay on Earth.