The questions that Severus was asking himself were quite different; why Nott had deteriorated (if in fact he had) and what exactly had set him off in the first place were not things he found particularly interesting. He was not impeded by anything like affection. He was mostly just intrigued - entertaining an academic curiosity as to what hurdles insanity would pose to art of choice. And if Nott improved, the details would be worth looking into a little more carefully.
He knew Malfoy had arrived, and he had just descended from his office to make his way out of the castle - and there he was, nearly on the threshold of the staircase. Severus regarded him, blank, as the gargoyle leapt back into place behind him. "Welcome back," he said, rather dry. "Did we have any other business?" He didn't think so.