The cold open: In television, it’s a scene that begins an episode before the title sequence, often without leading characters but almost always with foreshadowing hooks to confound or set a mood.

Theater doesn’t really have much of a cold open tradition. The expectation is that you introduce the main characters and get moving.

Not so for “Stranger Things: The First Shadow.” The new Broadway play, based on Netflix’s hit horror-science fiction series, starts with a bold five-minute cold open of loud gunfire, marauding Demogorgons and no leading characters. It’s a coup de théâtre, and it swiftly signals that the lead producers, the Broadway heavy-hitter Sonia Friedman and Netflix, are betting their big-money gamble will knock theatergoers’ socks right off.

Meet the Chicken Man