This is a very unfulfilling quest in the public dungeon. There are clues throughout that suggest a possible alternative ending, but no option is given. There should be an option to refuse to comply, as I suspect anyone who is paying attention would probably refuse to do so.
The NPCs ask you to sacrifice yourself to save them, but there are clues throughout that these three are actually the evil *** who made deals with the daedra that resulted in untold death and destruction. Only the very heroic would actually agree to help them. I suspect most people would choose to kill them, or at least leave them to their fate.
Many quests have two options at the end, and this particular one would be a prime candidate for a "moral" choice. The lack of options at the end is very jarring.
Yeah, okay, no big deal really, just odd that's all.