PG-13, 141 minutes. Through today only at Westbrook. Still playing at Waterford, Lisbon.

Fans and critics may disagree over when exactly the “Fast & Furious” franchise jumped the shark, but there is only one correct answer: When the Pontiac Fiero went into space. Weightless and violating every physical law, the floating car — tasked with bumping a satellite in the ninth installment — was the very symbol of how bloated and crazed the once-plucky series had become. There really was no way down after that. And yet we have come to 10, part of a planned series of films finally saying goodbye. “Fast X” is, thankfully, shackled to Earth’s gravity — sometimes tenuously, it must be said — but it has become almost camp, as if it breathed in too much of its own fumes. “Fast X” reaches into the fifth movie — 2011’s “Fast Five” — for the seeds to tell a new story. In a memorable moment five movies ago, Vin Diesel’s Dom Toretto wrecked a bad guy and his team on a bridge in Rio de Janeiro. Little did we know then, but that bad guy had a son who survived and now, years later, vows vengeance. That’s it. That’s the plot. That said, “Fast X” is monstrously silly and stupidly entertaining — just Wile E. Coyote stuff, ridiculous stunts employing insane G-forces and everything seemingly on fire. There are elements of “Mission: Impossible,” 007 and “John Wick,” as if all the action franchises were somehow merging. But here’s a warning: It careens to an end without a payoff, a more dangerous stunt than any in the movies themselves.