Loki had already been completely overwhelmed and driven to a place of irrationality. The subsequent events made little sense to him, confusion and pain both emotional and physical, the sound of Sif's scream echoing in his ears, the new betrayal by Odin.

He'd tried to speak, tried to say anything - This was for you! I was doing this for you! - but his words had been lost in the void.

And then he hit the ground, dirt filling his mouth. More confusion, sounds and foreign smells and shouting and sudden, blinding light--

Loki scrambled to his feet, hand grasping air for a dagger that would not come - my magic, I'm so empty, what - and then he tore one of the few he carried normally from the sheathe hidden by his coat. All he could really take in with a mind already taxed was the sight of Thor, sprawled out on the ground and obviously wounded, his presumed attackers already at him.

"Brother!" Intellectually, he knew Thor was no longer his brother, had never been his brother, but in this moment of frantic concern, intellect was overtaken by instinct. Loki threw the knife at Thor's presumed attacker, already tearing another, smaller dagger from his boot as he surged toward the man.

And ridiculously, it felt good to finally have something to fight, other than himself.