Gunman's Bluff by Edgar Wallace

The general manager of Maddison's Bank was not a man who could easily be taken by surprise. He had the fatalistic qualities which are peculiar to all men engaged in the business of finance. The vagaries of markets, the incidence of bank rates, and the fluctuations of trade left him unmoved. He had once been held up by an armed robber and did not so much as change colour.

Yet he stared with amazement and was physically incapable of coherent speech when he saw Luke Maddison walk through the outer office toward his private room.