one o'clock
But there seemed to be nothing for it but to wait there until morning , at least . `` We 'll stay here , '' she said , as good-nights were being exchanged , `` but we 'll set a guard for the night . Margery , I wish you and Mary King would take the first watch . You 'll be relieved at one o'clock . You 're not too tired , are you ? '' `` No , indeed , '' said both girls . `` I think I ought to take the watch .