It is the quietest and meekest people who are often capable of the most sudden and unexpected violences for the reason that when their control does snap, it goes entirely. (Hercule Poirot)
He was the meekest of his sex, the mildest of little men. He sidled in and out of a room, to take up the less space. He walked as softly as the Ghost in Hamlet, and more slowly. He carried his head on one side, partly in modest depreciation of himself, partly in modest propitiation of everybody else.