The Impossible Astronaut - S6-E2
Audio problem: When the Doctor sits in the Oval Office chair, Secret Service Agents aim their revolvers at him. As they do, the sound of a pistol slide racking is heard. None of them are doing anything except raising and aiming their revolvers at him.
Chosen answer: The Master knows that deep down, he deserves death for the crimes that he's committed throughout his life, and since he regards The Doctor as his arch-foe, he expects it to be at his hands. The fact that The Doctor is still willing to forgive him for all of his crimes hurts him more deeply than death would.
Captain Defenestrator