In response to your signature: Are we really sinking...this low_?
Also, for the last verse, when he is alone as they have separated, the music is empathetic to the lyrics. This is something Radiohead do brilliantly, and I have yet to hear a band come close to achieveing such synchronicity (is that even a word?).
Thom is alone and empty, and there is no guitar. Just sentimental voice, bass and drum. The contrast is amazing, and the deep instruments echo has feelings of emptiness.