It's like in the films. Kill a human and the audience doesn't care. Kill a dog and everyone's crying their eyes out.
[They reach her door and Martha turns the key.]
Never really understood the thought process behind it. Then again, most people witness animal deaths far more than human deaths...
[Door open, she gestures to let him through. The flat is much cleaner than the last time he saw it. It even smells clean. You'd never be able to tell someone was dealing with the flu from hell here.]