'OK. What is that?' asked Amy, shouting over the shrill bleeping noise that screamed out of the console. 'It's a signal! the Doctor replied, never once taking his eyes away from the screen before him. 'A beacon. An alarm. No... It's stranger than that.' All at once the TARDIS shook violently, nearly knocking them both off their feet. 'And what was that?' said Amy, bracing herself and struggling to keep balance. 'Well, I'm not sure what that was,' said the Doctor. 'I think we may have hit some sort of gravitational speed bump.' 'A gravitational speed bump? They have speed bumps in space? How fast were we going?'