[It's not even that Aki doesn't believe him -- Shinji has never steered him wrong before, but Akihiko has never been the 'wait and see' type. The more information withheld, the more ominous the situation seems, and the uneasier he feels about leaving Shinji to his own devices.]

I'd listen. You're clearly not going to explain, so just do me one favor. Just promise me you're alright, if you can do that honestly. I'll stay with Miki and check on Mitsuru, but your safety is important to me, too.