Question marks and multiple clauses between em dashes? Capitalization?

Question

Suppose a sentence like this:

The same museum guard I foiled last month was stomping over. Evidently, something about my disguise didn't pass muster — maybe it was the wig — but I managed to cut a long gash in the painting before he tackled me to the floor.

So far, so good. But:

Evidently, something about my disguise didn't pass muster — was it the wig? The fake nose? — but I managed to cut a long gash in the painting before he tackled me to the floor.

First, is this an acceptable use of dashes? It wouldn't feel right to move the questions to the end of the sentence, because it has already moved on. But with two in there, it's a little busy, and the capitalization seems inconsistent. And how else might we do it?

Evidently, something about my disguise didn't pass muster — Was it the wig? The fake nose? — but I managed to cut a long gash in the painting before he tackled me to the floor.

Here the questions are treated as distinct sentences by capitalizing them, but I think it might make coming back to the original sentence more awkward.

Evidently, something about my disguise didn't pass muster — was it the wig? the fake nose? — but I managed to cut a long gash in the painting before he tackled me to the floor.

Here both questions remain uncapitalized, but it might feel a little sloppy or casual. Tell me what you think.

Edit: I wrote this sentence just for the question, actually hoping to avoid being bogged down by too much context, but since the first commenter felt it was lacking, I've adjusted the text a little bit. True, I could work around this sentence construction entirely, although it would impact the pacing. I also think it would shift the sense of the precise moment this character spends considering the flaws of their disguise.

As for the single em dash suggestion provided: "I didn't fool him — was it the wig? The fake nose? Either way, I managed." That can work, and I appreciate the answer. So would you say that I'm conclusively not allowed to do this with em dashes?

Answer 1

First, your em-dash usage is fine. Here is a nice summary of em-dash guidelines. You've used them in your example sentences as a parenthetical aside, which is the primary usage according to the guidelines I linked. As a writer, I feel you've done the right thing to make the text lively and engaging by putting those questions there set off by dashes.

Second, the linked related question (and its related question) will tell you that the questions should have initial caps thus, even if they are fragments:

Evidently, something about my disguise didn't pass muster — Was it the wig? The fake nose? — but I managed to cut a long gash in the painting before he tackled me to the floor.

However and also, it is a guideline, not a rule. Personally, I feel that if you want to emphasize that the narrator interrupted himself with some thoughts that just occurred to him while he was relating the story, I would capitalize neither of questions as a means of suggesting that inner thinking.

Evidently, something about my disguise didn't pass muster — was it the wig? the fake nose? — but I managed to cut a long gash in the painting before he tackled me to the floor.

In any case, I would not recommend mixing the case, with one capitalized and the other not. I think that would be jarring to the reader regardless of how proper it might otherwise be orthographically speaking.