midnight
`` This woman , '' thinks Mr. Tulkinghorn , standing on the hearth , again a dark object closing up her view , `` is a study . '' He studies her at his leisure , not speaking for a time . She too studies something at her leisure . She is not the first to speak , appearing indeed so unlikely to be so , though he stood there until midnight , that even he is driven upon breaking silence . `` Lady Dedlock , the most disagreeable part of this business interview remains , but it is business . Our agreement is broken . A lady of your sense and strength of character will be prepared for my now declaring it void and taking my own course . ''