midnight exactly
its strange voice asked . `` Unless the one at your earth station has its receiver operating at the right moment you will simply flash on endlessly as radio waves -- will be annihilated . '' Milton found the courage to smile . `` We started from earth at our midnight exactly , and at midnight exactly twenty-four earth hours later , we are to flash back and the receiver will be awaiting us . '' There was silence when he had said that , a silence that seemed to Randall 's strained mind to have become suddenly tense , sinister . The great triple-bodied creature before them considered them again , its eyes moving over them , and when it again spoke the hissing words came very slowly . `` Twenty-four earth hours , '' it said ; `` and then your receiver on earth will be awaiting you .