Why did the Fairy Queen have to die at all in the 3rd season of The Magicians?
First, the deal makes no sense to me because there's no way Irene or any single human can guarantee that faeries won't be hunted (especially given the magic rationing that began shortly after), even if the Queen somehow knew they'd succeed with their Siphoning.
Let's not forget the fact that this deal actually refers to non-fairies, which includes not only humans but all creatures including magical creatures well outside the purview of humanity. Does this deal get broken when any creature hunts and kills a fairy? Who knows? If you must make a deal, why not something more sensible like making them promise to protect the Fairies if they are ever hunted by others?
But the main issue is the Queen didn't have to die at all. If Irene was somehow 'authorized' to make this deal, then the acting High King of Fillory should definitely be no less capable. Fen could've made the deal and with the help of the Queen, imprisoned (or killed really, they took care of the other McAllisters just fine) Irene till the Questers were done.
Instead we have a silly deal that doesn't favour either party (not for very long anyways), the Queen dies, Fen looks on as they cut up the body in her own palace and the Library gets the power it needs to execute the Siphon plan.
So, the question here is, is this actually a giant plot hole? Is there some sensible explanation that I'm missing?