The Doctor and the Ponds puzzle over an unlikely invasion of Earth, as millions of sinister black cubes arrive overnight, almost like presents falling from the sky. But what are they, what is inside them and, most importantly, who sent them? With the international community at a loss, it is left to the Doctor to unearth who is behind the mystery.
The Doctor (Matt Smith) spends time on Earth with his travelling companions Amy Pond (Karen Gillan) and her husband Rory (Arthur Darvill) while he awaits activity from millions of small cubes that appeared overnight.
“The Power of Three” focused on Amy and Rory’s point of view and the impact of the Doctor’s influence on their lives, as they would be leaving in the next episode. The story was inspired by The Man Who Came to Dinner and the story of the MSC Napoli. The episode also saw the return of UNIT and introduced their new scientific advisor, Kate Stewart (Jemma Redgrave), daughter of Brigadier Lethbridge-Stewart. The episode featured brief cameo appearances by Lord Sugar and Professor Brian Cox.