the aftermath of Rose's unwanted advances.

We're all going to be exterminated. Daleks were seen crossing the Westminster bridge and humanity's destruction can't be far behind. Help us, Doctor!

Okay, what's really happening is the filming of a scene from "An Adventure in Time and Space," the 50th anniversary special of Doctor Who. They're recreating the classic scene from 1964′s "The Dalek Invasion of Earth," and making a very strange day for anyone travelling across Westminster Bridge.