Even hardened cynics can't deny there's something a little thrilling about the idea of a crossover episode between two beloved TV shows. Or three. Or four. Knowing that the characters you love are kicking around in the same universe as one another carries with it a promise of combined forces and a larger imaginary world. But how do you artfully handle a crossover? Can they be done subtly? How do you avoid just tossing a bunch of people in a televised blender and hoping the result is worth watching? In this week's "Secret History of Television," we investigate the long, metafictional story of crossovers, from their early days in the worlds of Batman and the Green Hornet all the way up to recent blockbuster team-ups.
Tune in every Wednesday for new episodes of "Vulture's Secret History of Television," and be sure to watch our past installments, like our analysis of Cousin Oliver syndrome and our appreciation of bottle episodes.