Which theme is most present in this stanza? --
"There wasn't a breath in that land of death, and I hurried, horror-driven,
With a corpse half hid that I couldn't get rid, because of a promise given;
It was lashed to the sleigh, and it seemed to say: 'You may tax your brawn and brains,
But you promised true, and it's up to you to cremate those last remains.'"