Mistrustful, fighting to stay conscious, the Horcrux trained his wand first on the Potion Master and then on the Death Eater, clearly undecided if he should allow them close. So, Severus pressed on, "You are running on borrowed energy. You could be harming Ron and Hermione. Harry won't like that. We'll just get them into bed. Barty can guard them. You trust him, don't you?"