[Oh... He didn't actually expect a response quite like that, because he didn't want to imagine a hypothetical situation in which Iago was dead. That much is evident on his expression as he seems to go numb for the briefest of moments. Thankfully the conversation is redirected in time for it to really set in.]

O-Of course we will! After all, we are the ones who will unravel this mess of a web! Dying is not and never was an option!

[He reaffirms a prior conversation of theirs with just a bit more force than was really needed. Maybe if he says it louder, it will make it all the more true in the end.]