Ray Nelson’s Eight O’Clock in the Morning (1963) (http://bit.ly/2dS0oPH)
At the end of the show the hypnotist told his subjects, “Awake.”
Something unusual happened.
One of the subjects awoke all the way. This had never happened before. His name was George Nada and he blinked out at the sea of faces in the theatre, at first unaware of anything out of the ordinary. Then he noticed, spotted here and there in the crowd, the non-human faces, the faces of the Fascinators. They had been there all along, of course, but only George was really awake, so only George recognized them for what they were. He understood everything in a flash, including the fact that if he were to give any outward sign, the Fascinators would instantly command him to return to his former state, and he would obey.