three o'clock
I have discovered the remedy and I 've brought it with me . '' She took a sealed envelope from the inside pocket of her driving-coat and laid it on the desk before him . `` I 'm going to ask you to lock that up in your office safe for a little while , just as it is , '' she went on . `` If there are no signs of improvement in the sick situation by three o'clock , you are to open it -- you and Mr. Griswold -- and read the contents . Then you will know exactly what to do , and how to go about it . '' Her lip was trembling when she got through , and he saw it . `` What have you done , Margery ? ''