This is hard to split into two parts non-awkwardly. It's 私の格納庫に なにか御用？

The first bit is easy - 'my aircraft hangar (in)'. The second is a little ambiguous. It's 'nanika goyou?' which is 'is there any official business?' but more colloquially can be 'can I help you with?'

So you could read it as 'Just what the hell were you trying to do with my hangar?' or you could read it as 'Admiral's gonna get raeped.' Either way, great expression.

This is based on her new secretary line that was added earlier this week,

「私の格納庫に何か御用？　そう…んっ…大概にしてほしいものね。」

Which is something like,

"Do you have some business with my hangar? I see, well... Don't get carried away."

Kaga says this totally deadpan, as she says almost everything.

Ah, that explains it, thanks. And as drawn I think you can still read it the way you prefer. :)