Hmm.

[ She means to say 'yes', but that means being publically vulnerable in even the slightest way.

And there's no way Alice wants to do that, so all she gives him in return is a hum. ]

Perhaps you just need to think about something else for a while, and then the solution to the way you feel now might suddenly come to you later, after thinking about the other thing. Like why a raven is like a writing desk, for example.