midnight
`` Why do you think it is not likely , Captain Passford ? '' asked the executive officer curiously . `` Because the Bronx is a fast vessel compared with most of the steamers of the navy , hardly any of which are good for more than twelve knots an hour , while this ship will make sixteen when she is driven , and fourteen under ordinary circumstances when we are not trying to save coal . Of course I have no idea what duty we are to perform , and I am not anxious to know till the time comes , though midnight is a rather odd time to open the envelope . '' `` Probably the odd time means something . '' `` No doubt of it ; for to-morrow morning by four bells we shall be off the passes of the Mississippi , and our mission may be up Lake Pontchartrain , or at Ship Island . But let that matter rest , for in three hours and a half we shall know all about it .