The pitch for The Boroughs is exactly what the cast suggests: Alfred Molina, Geena Davis, Alfre Woodard, and Bill Pullman live in a retirement community that gets invaded by an otherworldly threat, and they do something about it. Netflix premieres it May 21. The premise requires a tonal balance that is difficult to sustain — too much genre earnestness and the comedy collapses, too much winking at the audience and the suspense disappears — but the cast is experienced enough with tonal complexity that the possibility of something genuinely good is real.