At the behest of no demon.

Fenris was never fond of caves. He had never admitted it out loud— not even to Hawke when they wandered through what the elf believed to be every existing cavern in the vicinity of Kirkwall, attempting to offer aid —but a strangely tense sensation never ceased to overcome the ex-slave when the sky disappeared from his view. He was not one to wonder for causes, however, or bend over backwards to reason with his mind, and merely did his best to find consolation in slaying various abnormally large spiders and other potentially dangerous beings. 

This time was no different, at first. Hawke had gathered them to subdue a particularly dangerous group of runaway mages hiding within the Sundermount caverns, and the mage (Fenris was not entirely certain why Hawke had taken him with them) continuously attempted to make the case for their freedom.

Fenris had just managed to corner a particularly nasty rage demon in one of the side pockets of the tunnel (one of the mages turned to blood magic the instant Hawke mentioned returning to the Circle), when a flash of blue and a resonating voice, mixed with that of their so called healer reached his senses.

And then everything started happening really fast; the ground began to shake under a powerful spell, and in a flash of light the ceiling in front of Fenris began to crumble, large rocks falling in his path, his only exit, until...

Darkness.

Darkness and... pain. Somewhere in his left leg, and his nerves slowly registering that which his eyes could not see - his leg had been trapped under a wall of rocks. Fenris let out a groan of both pain and frustration as his attempt to pull it out ended unsuccessfully.

"Venhedis."

When his calls to the rest of his party members yielded in nothing but echoes, a terrible realization dawned on him; they could not hear him. He was alone.

"There is no way out."

"I never wanted anything from you."

"I like to keep to myself, thank you."

"I was dead when I woke up this morning."

"My heart is hollow now."

"They're coming to get you."

"There's a drumming noise inside my head."

"Tell me what you want me to say."

"Leave all your love behind and run."

"There's no light in your eyes."

"I'l be dead before the day is done."

"It's over. And I'm going under."

"It's peaceful in the deep. No need to pray, no need to speak."

"I found the devil in me looking for heaven."

"A kiss with a fist is better than none."

"You are the space in my bed."

"If you're gone, I will not belong here."

"I was just looking for a breath of life."

"I can stay in the dark if you need me to."

"I don't want your money. I don't want your crown. I've come to burn your kingdom down."

"Whose side are you on?"

"Sooner or later, you love the things you lose."

"Would you leave me if I told you what I've done?"

"Never let me go."

"All your love will be exorcised."

"I can hear your heart beat."

"What has been done can not be undone."

"You left me in the dark. What was I supposed to do?"

"I'm damned if I do, and I'm damned if I don't."

"You'll carry it with you if you want to survive.'

"A thousand armies couldn't keep me out."

"The room was so quiet..."

"Things go wrong no matter what I do!"

"You were a falling star, and I caught you."

"You're my head, you're my heart."

"Though the pressure's hard to take, it's the only way I can escape."

"It's hard to dance with the devil on your back."

"You don't have to be afraid anymore."

"They're in my head. They won't shut up."

"I never knew daylight could be so violent."

"What's the point in living?"

"They were there when I woke up this morning."

"I know I can count on you."

"Sometimes I just feel like saying I don't care."

"I'm always in this twilight in the shadow of your heart."

"I started to hear it again.."

"I can't leave the past behind."

"You've got the love I need."

"The dog days are over."

"You can't choose what fades away and what stays."

"Life is just too much."

"I was looking to get a dream of life again."

"...I require no aid from a mage."