Arnora Auria is alive!

[nonameyet]

So, this only applies if you talk to Arnora after talking to Jorundr and decide to do things her way. Most may not know it, but she is a somewhat capable mage, making this more plausible. When you go to get Jorundr's loot and are accosted by the guard 'Tyrellius?,' he tells you he took care of Arnora.
If you defeat him and check his corpse, her (fake) amulet is not there, nor is it on her corpse when you return to her house. Noone involved seems to have it, and it seems to have disappeared. On top of that, if you notice the house's owner is dead and try to inhabit the house, it still says 'you cannot sleep in an owned bed,' despite the fact that Arnora is now clearly dead.
The wikis would tell you that this is just a bug due to the way Arnora Auria is disabled by the quest (not killed) and replaced by the dead npc Arnora (no last name).
I would propose the theory that Arnora Auria escaped and, possibly using magic, created or found a body double to fake her death. Why would she do this when you're bringing her back gold?
Because throughout the quest, she's never so naive as to simply trust you to give her the gold. It seems Tyrellius was actually an agent of hers (probably seduced), sent to eliminate you and bring the rewards back to her. When you slay him, she fakes her death and makes a quick escape, with her blue amulet.

[Legate Lanius]

Omg you may be right...