The pronoun change from "we" to "I" from the first to second main lyrical bodies is important, where in the first lyrical body, the singer puts emphasis on the couple with the repetition of "we" which takes away focus from the first singer's self, while the second singer's repetition of "I" is self-centered to place emphasis on what he sees and feels, for he can't experience the shared feelings of a couple with someone who isn't there.
The second main lyrical body is sung by a new singer who has a higher pitched voice, and it is broken up into three main parts where the singer changes his thought processes, as if he's thinking about so many different things at once. His first thought sequence starts with "Where..." and ends with "...time," where the singer expresses a heavy reliance on his loved one and describes the emotional impact of her absence on him; the first line begins with him asking where his loved one is and apologizing, perhaps after an argument that occured late one night. He then says "I need somebody and always this sick strange darkness comes creeping on so haunting every time." One key thing here is the singer's word choice of "somebody" instead of "you" which suggests that the singer doesn't care who loves him as long as they give him the love that he needs, so even the singer demonstrates a sublte lack of loyalty just as his loved one does, but it's justified because of her "treason." The other key thing here is the singer describing the darkness as "sick," "strange," and "haunting" which sets up contrast between the first singers understanding of darkness, who is completely enveloped in it, and the second singers understanding of darkness, or perhaps, the lack thereof for he sees it as a foreign and manevolent, while the latter sees it as native and intrinsic to his very being.