"Supposed?" Kirk asked. "I don't
Of course. (But if you're going to start with a capital after the quote mark, you will need a period -- not a comma -- beforehand.
Right you are. Fixed. I guess I got mixed up when I decided to have Kirk continue speaking, but with a new sentence. Thanks for being my punctuation-checker!
As for the ellipses, yeah, I can see how those might be appropriate, but I think they might just confuse matters further. I'll just stick with quotation marks myself, and to each their own.