Everyone forgets a line now and then. But a Philadelphia performance of a Tom Stoppard play last week spiralled out of control when one of the actors missed a line, then another and another. Finally, a script was deposited onstage and the poor actor made his way through recovery. “To anyone who has been onstage with much to do, not knowing what to do next, the experience is like the centipede stopping to think which of its many legs it should move – and becoming paralyzed. Quick recovery is possible. Or not. An actor spooked by the experience is cast out of the world of that character and into the cold, with no protection.”