seven o'clock
Musgrave turned to Nick . `` I have no special instructions , '' said Nick , `` except that you keep your eyes on the woman . '' The officer saluted , and vanished almost as quickly as he had come in . At half-past seven o'clock that evening Musgrave was on guard outside the flat , the address of which had been given to Nick by Jones . An old man selling papers came along the street , calling `` Extra ! '' in a cracked voice . Musgrave bought a paper .