She stands, flexing her wrists and fingers and then touches her unaffected hand to the intact flesh near the weird green light, and - carefully, not that that word means much from an Elric -

She forms an analysis circle of her body and mind. 

What is this thing? 

It's-

-a thing. Maybe?

Hard to tell. Pure energy, except for all the ways it's not really what Bellona understands as energy. If it were pure energy, her hand and everything in, say, a five-meter radius should be very on fire right now. Possibly the closest analogue she's encountered is the Gate, but even that is a very imperfect metaphor.

It's attached through her hand, tangled around and into muscle and bone and blood- and as the mark flares again, if she concentrates through that she might be able to guess that where those overloads are crossing her nerves is sending the pain signal.

Rerouting nerves is a pain in the ass, but, she's just gonna leave everything it's touching alone and wall it off, a layer of biologically inert graphite and her blood vessels and nerves and muscles redirected around it. This is going to cost her a lot of mobility in that hand, but, well - she's still better off than if she had automail.

This produces a very, very faint electrical discharge around her hands, more static electricity than anything, and a little flare of blue.

Everyone around her with swords draws them.

She lowers and separates her hands, a bit exasperated. "I walled this thing off from my body. That's all."

"Perhaps warn us first, next time? Unexpected magic makes people jumpy." Leliana waves everyone's swords down. "It's all right, Cassandra. We're going to have to trust her at least a little bit."

"Sure," she says. "I was planning to just look at it, which isn't visible, but it was... Entangled alarmingly, and I acted to protect myself."

"That's understandable." She sends a prompting look in Cassandra's direction.

"...Yes," she agrees grudgingly. "It is."

"Anyways - it's definitely not like anything I've encountered before, but it's something I can analyze and get data on. - I'm going to need writing materials at some point to record my observations, but, let's go see this hole in the sky first."

"Best to take her out the side, Cassandra. I'll meet you two at the bridge." And she leaves with the guards.

Well this is more awkward than it was with the reasonable one in the room. 

"So - what should I call you?"

"My name is Cassandra Pentaghast."

"So - Cassandra, Miss Pentaghast, commander...?"

"Cassandra will do. None of the titles will mean anything to you, if Leliana is correct."

"They probably won't."

"You can call me Lionheart."

"Lionheart."

"We should make our way out now. We've given them enough time."

She'll follow, then. 

Out the door and down the stone corridor. It doesn't look as though it was originally intended to be a prison, more of a secluded place for scholars and the storage of texts. The stairs lead up into a wide open room with a tall, steeply pitched wood roof crisscrossed by rafters. It seems to have been converted to an impromptu infirmary, with many wounded soldiers on cots being tended to by men and women in brown robes. The main double doors are to the left, but Cassandra instead takes her quickly across the room and around a corner where there are a small cluster of office-type rooms and a single door to the outside.

...Does she see any signs of modern technology? Electric lights or fans, firearms, automail, anything in the infirmary signaling any medical technology...?

There are washbasins, at least, and she sees at least one being swapped out for a clean one. But a firm 'no' on any sort of electrical technology.

...Probably the hole in the sky is more urgent.

Possibly, though, her greatest resource here will be her existing knowledge of technology and science...

"...People will continue to be hurt as long as the Breach is active," Cassandra says softly. "If you can fix that, we need to know now."

She looks her age for once, for a fleeting moment. (She carries herself like she's older and taller, but she's still pretty fundamentally an underfed teenager whose body hadn't moved in years, who still hasn't had time to build up the strength and stamina she had as a child, who was always going to be short.)

"Alchemy is slow, sometimes," she says. "I need to understand what I'm doing to fix things. I'm going to try, but - "

(She's been too late a lot of times.)

"If you can help in other ways, we would appreciate your assistance."