Swamped

You do have the mask that came here with you, but that still doesn't really address how to explain it. You're not sure you would have even realized what it was if you hadn't seen breather masks before.

And if they somehow do know what it is, they'll wonder if you have military connections. Which is an angle that seems more than a little odd.

Maybe making some suggestions would be best.

"It's not a necklace?"

"No, something was hanging off it. Didn't look like any jewelry I'd ever seen, either."

"So... not a scarf, then?"

They pause.

"Might have had a scarf. Yeah, hang on... they did, but this was hanging over it."

"A bottle, perhaps?"

They frown.

"Now, I think that was my first thought, because it was see-through. But then I thought it was a funny shape for a bottle. And there was something in it that I couldn't make any sense of."

"Oh! I think I saw something like that. Hold on for a moment."

You run off and return with the mask. The patient looks at it, startled.

"That's it! Well... without the purple bits, but it really looked a lot like that. What even is it? Where'd you get it?"

"They found it with me when I woke up. It's not mine, though."

The artist starts sketching furiously.

"Well, whoever it belongs to, it's good enough for me to get an outline down. Now I can work on fitting the face in. Surprised they didn't cover it up, but then, who knows what they were thinking."

A few minutes later, they show off their work.

"Very nice," you say. "Oh! But if they find it, and see the mask in there, they might start questioning me. Since it looks like the one I was found with."

"Wouldn't want to get you in trouble," they say. "Think that cleared my head good enough, anyhow, so you can hold onto it."

They hand over the picture.

"And now I can't draw your picture for the same reason. Eh, but I'll find something. Thanks again."

You suppose that's all you can do for now. You glance at the picture, but it doesn't really suggest anything immediately. Though, as this attacker is clean-shaven, it's unlikely to be the same cloaked figure you caught a glimpse of tonight.

Well. That leaves you with one other matter to investigate right now: a name that caught your attention.