Suddenly a widow

She saw the sheet of paper as she turned the corner into the corridor. "Ann. This is to warn you that when you open the door I will be dead," it read-and went on to accuse her of things as shocking as they were untrue.
In his room John Harrington's sprawled figure lay oddly twisted on the bed, his graying hair tousled, his face tinged with more color than it had held in life. The family thought it was his heart-the doctor had warned them that another coronary would be his last. Ann, who had destroyed the note, thought it was suicide-out of anger and bitterness at her. The police said it was murder! Either way Ann had to find out, for either way the finger of guilt was pointed directly at her.