What is the meaning of at that here?"You are thinking there might be something small about to happen, that's going to start a chain reaction . . . and we have a shot at stopping it?" I asked.
"Maybe."
"You are dreaming!" I shouted.
"I might be, at that. But I know we're here for a reason."
at that: 1) in addition 2)nevertheless 3)as it is
Nothing seems to fit. Any ideas?
'...now you mention it'. It's a way of referring to a possibility that you've only just considered.
(That's not a very satisfactory explanation - short words are the hardest! It's the best I can do though- I look forward to other glosses...)
b