Everyone thought that today would be just another normal extraction day. Only the girl knew that it wasn't.
She had laid down on the altar as usual, and as usual, a gust of wind came crashing down on her with a horrific pain that could kill someone. Except it had never killed her before.
When the ritual had finished, the knights came in and waited for the girl to get up so they could take her back to her cell. Usually they would go up there and take the child themselves, but they knew that the girl would always get up on her own, unlike the other children who would pass out from the pain, so they waited.
It didn't take even two minutes for them to get impatient. They went up to the altar and dragged her to her cell. She was unconscious, but that's to be expected. The children usually fall unconscious from the pain anyway. It was strange that this is the first, out of many, that the girl had passed out, but no one thought it out of the ordinary and so they left her alone.
They only found out the next day, when they came to get her for testing, that she was dead.