...of brooding

Albinus said nothing. At first, to be sure - while they were still in Switzerland - he had begged Paul with petulant persistency to ask Margot to come and see him; he had sworn that this final meeting would not last more than a moment. (And, indeed, would it take long to grope in the wonted darkness and, holding her tightly with one hand, to thrust the barrel of the automatic against her side and to stuff her with bullets?) Paul had obstinately refused to do as he asked, and after that Albinus had said nothing. He travelled to Berlin in silence, he arrived in silence and he was silent for the next three days, so that Elisabeth never heard his voice any more (except perhaps once): he might have been dumb as well as blind.

[Laughter in the Dark, Nabokov, V.]