For once, Isabel had no heart for asking questions.  She had expected whatever happened next to be strange and terrible, and it was indeed both, but this time she could only watch and wonder in unhappy silence as the Doctor performed his grim task.  Only the strange words he spoke just before he struck the killing blow truly caught her attention.  Her thirst for knowledge meant that she had learned at least a little of quite a few languages, even Greek and a little Arabic, but this language sounded like nothing she had ever heard before.<br/><br/>Nothing from this earth, she thought, and in that instant the blow was struck and William fell with a strange crackle of energy.<br/><br/>She wavered, only just catching her balance, and looked down at William quietly for a moment.  Then she realized the Doctor had spoken, this time in English, and she gave him a quick, grateful glance.<br/><br/>For a moment she knelt beside William, relieved to see that his eyes had closed of their own volition.  Perhaps that was a sign that he had found some measure of peace even in the moment of his death.  She murmured a brief prayer, then stood, still faintly unsteady, and turned to the Doctor.  "What manner of creature has done this and how can it be stopped?" she asked, quietly but with determination.