"Rrright. Can you make yourself not cover my entire body?"

«Such a course of action would reduce the protective function of the Blue Beetle armour,» the scarab protests. 

"Unless you're going to explode another lab, I don't need your 'protective function' right now."

This seems to do the trick.

«When not in a combat scenario, the Blue Beetle armour can be fully retracted.» It demonstrates. The exoskeleton retreats whence it came until the only visible portion is the scarab on her back. That part apparently doesn't 'retract'. 

"Great." Now to get out of here, inconspicuously, before emergency services show up.

Emergency services are only just beginning to appear. Some neighbor or passer-by must have finally realized that no-one else had called 911 yet. They'll be sufficiently distracted putting out fires and searching for survivors that Ellie can slip away unnoticed. 

...She might have to start wearing a jacket. For now, she's going home, where she can think about what the hell she's actually going to do about this in relative peace.

The scarab is quiet. If it wasn't for the palm-sized lump over her spine, she could almost forget it was there. It's relatively easily hidden by regular clothes, although anyone who touches her back will notice unless there's a lot of fabric in the way. 

That'll make school easier. Classes are, as usually, incredibly boring. The topic of the day is last night's explosion and it seems like everyone has their own stupid theory on what experiment went wrong. She participates as much as she usually in these sorts of gossip sessions, which is to say she doesn't. Though she does listen more carefully than usual.

After school she needs to swing by the mall to pick up some supplies for a group project. Her plan is to get that over and done with before dinner. The mall is far from her favorite place to be.

She's only part of the way through her list of supplies when the explosions start.

A thuggish guy in a hockey mask strides through the mall, carrying a tennis ball in one hand and a racket in the other. Seemingly at random, he stops and takes aim at a potted plant. He hits the ball in its direction...it bounces once...and explodes on impact with the plant pot.

Shoppers scream and run. 

He pulls another ball out of his pocket and weighs it thoughtfully in his hand as he looks around for another target. 

«The human is weak,» the scarab scoffs in Ellie's head. «His weapons are toys. We are far more powerful.» 

It begins listing off ways they could kill hockey mask dude.

"Considering that Superman exists, let's maybe not jump straight to disintegration," mutters Ellie as she ducks for cover like everyone else. "I'd prefer to not be hunted down by the Justice League at this point in my life. Can we just knock him out or something so I can finish buying my damn posterboard?"

«Non-lethal administration of sedatives requires precise knowledge of the target's body mass,» the scarab hisses back. 

...it supposes they could restrain him with extruded nanotech. That would be boring, though. 

"A thousand ways to kill someone and you don't have any sort of bullshit scanning that can read mass remotely. Wonderful." She needs to get somewhere out of sight before the scarab extends its suit again.

There's a counter she could duck behind? Or she could slip into that disabled bathroom just there if she wants more guaranteed privacy at the cost of a small delay. 

The man in the hockey mask continues to terrorise shoppers, and the mall is rapidly emptying around him. It doesn't look like anyone's been seriously injured yet, but some people have been hit with broken glass and the like. 

Bathroom it is.

"How does this extruded nanotech work?"