Gunman's Bluff by Edgar Wallace

For two days Margaret Leferre moved in a world of hideous unreality. Strange people interviewed her: a tall, big-framed man, who was strangely sympathetic in his heavy way, a bank manager who talked wildly and incomprehensibly until Danty appeared and whisked him off.

One thunderous fact hammered night and day at her weary brain -- Rex was dead by his own hand, and the man she was to marry, the man who, frantic with anxiety, was calling three times a day and being refused admission to her, was the cause. Money was his god!