Clark had been afraid it would be this one. She was in such bad shape when they rescued her, even if it wasn't physical... she had nightmares from this experience. And he doesn't fault her for it, not before, and certainly not now.

He wants to be able to close her eyes to this as he sees the glint of the knives in the vampires' hands, feeling her fear and grief like it's his own. The helplessness of being chained down, and unable to defend the children with her powers.