seven o'clock
One might leave there and walk down this passage naturally enough . '' Laverick inclined his head . `` As a matter of fact , '' he declared , `` I think that the evidence went to prove that there were no visitors in the restaurant that night . You see , all these offices round here close at six or seven o'clock , and the whole neighborhood becomes deserted . '' She shrugged her shoulders impatiently . `` Your English police , they do not know how to collect evidence . In the hands of Frenchmen , this mystery would have been solved long before now .