Liev Schreiber is opening up about a terrifying experience he had while acting in a play. During a recent appearance on "Late Night with Seth Meyers," Schreiber detailed the neurological disorder he experienced prior to going on stage to perform his role in the Broadway production of "Doubt: A Parable." "The worst nightmare that an actor could possibly ever experience," he told host Seth Meyers. "I was in my dressing room, and I had a terrible headache.