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.