...It might almost be easier to describe what magic cannot do. And even there- magic is an expression of a mage's connection to the Fade, and the Fade is the realm of dreams. Anything can happen in a dream-

-But further elaboration will have to wait, as the sound of clashing steel echoes ahead. "They are fighting at the rift. We must hurry."

She breaks out into a ground-eating jog, going quiet and intense, with an eye to finding somewhere sheltered to crouch as they reach the fighting. 

They're coming out of a scraggly bit of forest to a rocky space next to a small stream. The rift is a shimmering green sheet of silk hanging in mid-air, half a meter above the ground, about that wide, and three meters tall. There's a swarm of little green wisps and two towering ??lava monsters?? and a pair of soldiers and a short blond man with a very intricate-looking repeating crossbow and a bald man with pointy ears twirling a staff out of which blossoms a torrent of ice, taking out three wisps at once.

Cassandra charges, hitting one of the lava monsters in the side and knocking a fireball forming in its hand off course to sizzle in the water.

One: she claps her hands together. 

Two: she drops to one knee and slams her palms on the ground. 

Three: massive spikes of hard, sharp rock surge into each of the enemies. 

That deals handily with the wisps, and lets Cassandra and the others focus their attentions on the lava monsters, which were damaged but not destroyed by Lionheart's attack.

As the last one dissipates with one final roar, the bald man with pointy ears turns to Bellona and beckons her over. "Quickly!" he calls. "Before more come through!"

She heads over, intent on getting ahold of and analyzing this thing. 

The mark flares, reaching out to the rift, she can tell without even doing an analysis circle. It's almost magnetically attracted, trying to lift her hand up and towards the rift by itself. A subconscious synthesis flashes into understanding: if the rift is a door to another world, the mark is hinge and key to let her close and lock it. She has but to brandish the power and twist.

She probably shouldn't hold the rift open while she pokes it until she has better demon containment methods... Probably. Also until she's built up more trust with everyone around her. 

She taps her hands together lightly, at least, so she can watch what's happening as she twists the rift closed. 

It's like watching a wound heal in fast time, if flesh were cloth and that cloth were the skein of the world. Kind of hard to track, honestly.

And hard to make go any slower...

She's going to need to arrange experiments - with 'magic' in general - under controlled conditions.

"It worked..."

"Your 'magic' behaves oddly..." she comments. "But I don't think the mark is exactly like those rifts... They're related, but - different."

"Well yes," says the bald man. "Otherwise you would have spirits jumping out of your hand, would you not?"

"I'm not familiar with your magic, so, that's not actually obvious to me - it could be a difference of size, rather than kind."

"Ah. That mark and these rifts are connected in cause, it seems sure, but I believe that at best, only the mark was intended. The rifts are... splash damage, the term these days is."

     "Then it was a hell of a rock that got dropped, Chuckles," the short man says, ambling over. He's stowed his crossbow on a strap over his back, and wears a leather coat and v-necked shirt, both unlaced to expose a broad swath of his hairy chest, despite the chill in the air and the flakes of snow beginning to drift down. "And dwarves don't do so well at swimming. I for one am glad to be thrown a floater." He nods at Bellona in greeting. "Varric Tethras. Rogue, storyteller, and occasionally, unwelcome tagalong." He tosses a wink at Cassandra with this last.

She rolls her eyes.

Smile. "It's a pleasure to meet you. And, if we're doing full introductions - "

"The Lionheart Alchemist, Lieutenant Colonel Bellona Elric, State Alchemist of Amestris. Scientist, doctor, explorer, and - I've been told - all around pain in the ass. Call me Lionheart."

The dwarf cocks his head. "That's an impressive set of titles. Especially for- what are you, fifteen, sixteen?"

Laugh. "Later part of sixteen, though I've been a state alchemist for - what, five years now? So I suppose I should add 'prodigy' to all that."

The bald man smiles, a little. "Indeed, you are well-accomplished for one so young. My name is Solas, if there are to be introductions. It is a pleasure to meet you at last."

     "He means, 'I kept that mark from killing you while you slept'," Varric stages-whispers.

"What was it doing?"

"Attempting to grow beyond the limits your body could sustain. I was unable to sever the magic from you completely, but I limited the draw as best I could."

"You know a lot about magic, then..."

"I have studied it for most of my life. My travels have allowed me to learn much of the Fade."