three o'clock in the morning
`` Nothing , '' he answered . `` But this climate is making me insupportably drowsy ; or else the spring weather . '' `` Oh no ; it is n't that , '' she said , with a slight sigh . He had left her in the middle of a german at three o'clock in the morning , but she now looked as fresh and lambent as a star . `` It 's the late hours . They 're killing you . '' Colville tried to deny it ; his incoherencies dissolved themselves in a yawn , which he did not succeed in passing for a careless laugh .