Firefly Glen because you feel like a heartbeat

And just like that she looked at him like a monster. Why shouldn't she? 
He only knew one trade. One purpose. To take lives. But he wasn't..."This? No. This was an accident. Spar that got out of control. No, Clarence is very much alive." He did his best to stay still, watching her. She backpedaled, suddenly timid and submissive. 
"You have just as much right to speak as I do...it's ok. Anyone would be... afraid..." He had never met anyone like her. She spoke like one of the slaves Nix had kept for breeding and den duties- soft, timid, frightened. 
And there it was. Her eyes darting anxiously, waiting for him to lunge at her, or for some unseen band of killers to lunge at her. 
"Fen...if it's ok for me to call you that?" his voice was soft, trying to be as gentle as he could be, rolling to his stomach but still staying below her. He was like some rennaisance portrait, a demon laid down at the feet of an angel. 
"Who hurt you? I know that look. That feeling like something horrible is just behind you, something no one else sees." He wanted to protect her. He wanted to destroy whatever had reduced such a kind being to a trembling, shrinking thing.