I am looking at the FAQ flow chart for the action window framework and have yet another question that needs clarification. Let's say my opponent plays a card to kill a character. I respond with a save. My opponent responds with paper shield to cancel the save. Is my opponent allowed to respond to my save directly or are players only allowed to respond to the initial card being saved/killed in this step of the framework?

During a save/cancel step, players can trigger any responses that have the words "save" or "cancel" in them, provided that their play restrictions are met. Play restrictions are any part of the response that tells you when or how often you can trigger the response. So yes, using Paper Shield to cancel an event-based save like Risen from the Sea is perfectly acceptable.

If you want to delve deeper into the minutiae of save/cancel responses, you could read this article:

http://www.cardgamedb.com/index.php/index.html/_/game-of-thrones/quill-tankard-regulars-issue-12-r312

Just to make sure:

Saves and cancels are the only true interrupts in the game. They are the only thing that can be triggered after something is initiated, but before it resolves. More to the point, they have to be played after the initiation but before the resolution of whatever they are trying to cancel. So, since the nature of saves/cancels is to interrupt, you effectively create the opportunity to play a save or a cancel every time you initiate another effect.

So yes, your opponent can "Respond" to your save - as opposed to the original killing effect - with a cancel because that's what cancels do. The flow chart doesn't show this possibility that you could have a chain of "interrupts interrupting interrupts."

That's what I thought. Just wanted to make sure. Thanks once again.