There are genuine, body-tensing moments of terror and amazement in "Harry Potter and the Cursed Child" that might cause one to wonder, perhaps aloud to a seatmate, whether an ambulance is on standby outside the theater if, say, there's a mishap with one of the flame-throwing wands.
Heat from the flames can be felt on faces in the crowd.
Without giving away too much, there's also a man-eating book shelf, pulses that somehow rock the theater in moments of time travel and a potion that mutates one character into an entirely different human.
