Well. You shouldn’t need that much pressure on his throat to keep from him shouting louder than Arlene. So the only thing you need to do is keep her talking.
Unfortunately, she’s not in your troupe, so you can’t really use any of the familiar signals.
But then it strikes you that you don’t really need to be subtle.
“You damn fool!” you shout suddenly. “You’re just making it angry!”
He’s confused for a moment, which is enough of an opening to hit your head against his neck. That gives you a chance to push harder on his wrist, and his grip on you loosens just as you hear him start to call out.
But it’s too late. Arlene’s already filled the air with a ferocious roar. One of the best you’ve heard, actually. For a moment you consider trying to recruit her for the troupe, then you think about what it would like to have both her and Mina around and think better of it.
Regardless, you can’t hear what the gang member is saying, and a few moments later, you put him out cold. Hopefully, by the time he wakes up it won’t matter what he tells anyone.
Just for effect, you let out a loud scream. Then you get back behind the costume and continue lugging it. You don’t hear any more gang members as you approach the room.
But now comes the real problem. There’s a wizard in there. You have the costume, and you’ve got Arlene making sounds, wherever she is, but making the thing move is going to mean standing uncomfortably close.
So you’ll need to be very careful in how you approach this.