When the TARDIS materializes north of Stalingrad in 1942, the Doctor, Jamie, Ben and Polly are captured by the Night Witches, an all-female unit of flyers tasked with disrupting the German forces nearing Moscow.
The TARDIS takes the Doctor, Ben, Polly and Jamie to a flooded underground town on an alien world. The streets are empty. The houses are bare. Not a trace of life.
When the TARDIS lands in London, Ben and Polly are initially delighted to be back home - until they realize that they're a hundred years too early. But this is nothing next to how the Doctor and Jamie feel when the TARDIS itself vanishes.
