In “The World’s End” (pictured), Simon Pegg and Nick Frost invert their familiar screen dynamic, with Pegg playing the bad influence.
Now Pegg, Frost, and Wright are back with “The World’s End,” a sci-fi comedy that brought them to Boston for a recent publicity stop. Naturally, they also hit a requisite, sold-out Brattle marathon of their “Three Flavours Cornetto’’ trilogy, so named for an ice cream novelty that pops up in all three of their movies, as diehards have obsessively noted. It’s an inside joke that’s part Kieslowski, part Nutty Buddy. We repeat: cult sensation.