Movies in the Fast & Furious franchise really ought to come with a warning. Not about the extravagant violence and sky-high body counts, but about the sheer idiocy that defines these movies. Oh, they are entertaining and frequently hilarious in their doltish way but watching them is a good way to kill off brain cells. F9, the dumbest entry in moviedom’s dumbest franchise, will murder many.

Like Michael Corleone once lamented, “Just when I thought I was out, they pull me back in,” so it is with Dom Toretto (Vin Diesel). Living in exile on an isolated farm with Letty (Michelle Rodriguez) and his young son, Little Brian (yes, “Little” Brian – as if anyone would mistake a small child for the late Paul Walker after whose character he’s named), he has put his old life behind him. At least, until Roman (Tyrese Gibson), Tej (Chris ‘Ludacris’ Bridges), and Ramsey (Nathalie Emmanuel) show up to enlist Dom and Letty into a new caper with the fate of the world in balance. Those snobs at MI6 or IMF have got nothing on these gearheads charged with recovering a device that could alter the world order – and with putting to right Dom Toretto’s world.

The first hint that something biblical is on the menu happens when Dom is still on the farm, putting Little Brian to bed, telling the boy that God lives in his heart. Then he says, “I live in your heart.” Does this mean Dom is God? In his own mind, certainly. But the theme continues when it turns out that the nemesis he must vanquish this time out is his own brother Jakob (once and future WWE fighter John Cena). The Cain-and-Abel vibe is unmistakable, sibling rivalry turned into sibling warfare (and often sibling hand-to-hand combat, that is when they aren’t trying to outdrive each other). Flashbacks reveal the heart of the beef between these warring brothers with daddy issues.

The Dom and Jakob reunion is not the only one in F9, as this is a film that assembles as much of the crew as possible, both friends – including Dom and Jakob’s sister Mia (Jordana Brewster), Han (Sung Kang), and Sean (Lucas Black) – and Dom’s foe Cipher (Charlize Theron, slumming to the point where the Academy might want its Oscar back). Even Deckard Shaw’s (Jason Statham) thieving mum, Queenie, shows up, Helen Mirren adding a touch of regal class to this live-action cartoon. (To catch sight of Statham, stay for the end credits.) F9 is not the end of the franchise, but if it had finished here, it would have been given a proper burial.

Instead, the will soldier on, despite the fact that there are really only so many ways you can crash cars and director Justin Lin and the writers are clearly beginning to run out of ideas on that score. The non-driving Ramsey learns on the fly, steering a big box truck down the narrow streets of Edinburgh, Scotland, the vehicle equipped with high power magnets, so that the chase becomes one of high-powered, explosive bumper cars. So far, so funny, but then the magnet gag keeps getting repeated. And, sure, that helps pad out the running time, but it loses steam through rote repetition. A more inspired (and lunatic) bit plants Roman and Tej in a rocket-equipped car – and, well, cue the Space X jokes.

F9 left me yearning for the return of SCTV and Joe Flaherty and the late John Candy’s “Farm Report” where a pair of cinephile farmers acted as the rural answer to Gene Siskel and Roger Ebert. They would have cut to the chase and distilled F9 to its very essence: “Stuff blowed up real good.” Yes, yes, it did. –Pam Grady