midnight
`` You turn in , Mac , '' he said . `` You 're about bushed after the work you 've done to-day . I 'll keep first watch . I 'll conceal myself fifty or sixty yards from camp , and if we have visitors before midnight the fun will all be mine . '' He knew that MacDonald was asleep within fifteen minutes after he had stationed himself at his post . In spite of the fact that he had had almost no sleep the preceding night , he was more than usually wakeful . He was filled with a curious feeling that events were impending .