It was a moving echo of the season one finale, that had been soundtracked by Buckley's version.
However, Heap was initially reluctant to take on such a well-worn anthem. She explains in the book:
"I had actually just sent an e-mail to the show saying I was sorry, but I wouldn't be able to give this the time it requires. I was in the shower and feeling a bit sad about it, and I started singing it and thought, 'Why don't I just do it this way—do it a cappella, with no music or production, as if I were singing in the shower?' So I got out and I sent them another e-mail back."