The Doctor's panic rises when he hears someone coming along and automatically, he flings an arm out in desperate, uncoordinated, giraffe-like panic to prevent him from getting within reaching range of the angel for fear of what it might do. "Back!" he warns, as stringently as he can despite the massive thought processes circling through his mind. "Stay back, back! And don't blink."

One of them is going to have to close the door because the lights appear to be dimming, which is far, far from being a good sign.