The demon goads him, stretches Dean's head back to show the length of his neck, blood pulsing under thin skin. The thing can sense Sam's weakening power, he's sure of it, and it only makes him angry, jaw clenched tight and the pain nearly enough to make him black out as he pushes through it, tries to cling to the last tendrils of the darkened soul that slip from his grasp.

A fresh spike of pain splits down his skull and Sam cries out again as he drops his arm, gasping and shaking, crumpling under the weight of defeat and failure.

"Dean," he breathes, knees nearly buckling once more as a drop of blood spills from his nose and onto the cold floor at his feet.