They stopped putting numbers on Tom Cruise's Mission: Impossible films at three. Rogue Nation is the fifth.
Other than the stunts which interrupted them, it's hard to actually remember what actually the stories were in parts I to IV or what they had to do with each other.
The memory of narrative details tended to self-destruct five minutes after leaving the cinema.
That said, it could be said the spy franchise based, increasingly tenuously, on the late 1966-73 tv show is actually getting better as it goes along.
This one isn't exactly Le Carre as a story either. But its battle between Ethan Hunt and his cohorts against a foe that may or may not be imaginary combined with some impressive action and a few less locations all help make Rogue Nation a smarter faster movie than the last one.
That predecessor, Ghost Protocol, was the highest grossing in the series. That was despite Cruise's increasingly awkward public profile and that the response to his other popcorn flicks of recent times - Knight and Day, Jack Reacher, Oblivion, Edge of Tomorrow - showed his drawing power was on the wane.
But maybe the M:I series lives on in good health not because it's become an American Bond, but it's less about Cruise and more of a team-building exercise.
Rogue Nation is Brit Simon Pegg's third film as The Impossible Mission Force's head geek Benji Dunn. This time he's gone from the guy from IT to fully fledged comedy sidekick to Cruise's Ethan Hunt.
Pegg helps make this the funniest M:I yet, as does Alec Baldwin as the CIA boss who wants to bring the Impossible Mission Force squad back under his control and attempts to burst a blood vessel in his every spoken proclamation.
It may be funnier but it's also darker than its globetrotting immediate predecessor and feels more like a Euro-espionage thriller than a spy story stuck on an action chassis.
In some ways this has echoes of the original Mission: Impossible movie directed by Brian de Palma, who routinely imitated the thriller conventions that Hitchcock invented.
Here director Christopher McQuarrie, who directed Cruise in Jack Reacher, has his own Hitchcock moves - in a scene set against a performance of Turandot in the Vienna State Opera which recalls the Royal Albert Hall assassination scene in The Man Who Knew Too Much - the 1956 movie, which, like Rogue Nation also takes an excursion to Morocco.
Then again, it's possibly inevitable that McQuarrie, whose first feature writing credit was The Usual Suspects, would find his way to Casablanca.
Its air miles might be lower but it doesn't lack for adrenaline moments. Already the film's trademark bit of derring do - Cruise's hanging onto the outside of a cargo plane as it takes off with its load of chemical weapons for Chechen forces - is all over in the film's Bond-like preamble.
There are plenty more high-speed excitement involving high-flying cars, hard-leaning motorcycles and pointy-handed running through dark London alleys.
In one deeply breathless moment Hunt plunges through a supercomputer water-cooling system to swap some hardware.
Quite why Hunt is doing the equivalent of a free-dive into a giant washing machine to change a fuse in the middle of a spin cycle possibly doesn't stand up to too much contemplation of logic or plausibility.
But the action quotient of Rogue Nation is satisfyingly high, pushes the story along and shows Cruise is still earning his danger money.
That said, as well as the comedic foil of Pegg, Cruise is also sharing plenty of screen time with newcomer Rebecca Ferguson as a British agent who has gone undercover - or has she signed up? - with The Syndicate, a shadowy multinational terror group dead set on the sort of global disruption that comes with being a a shadowy multinational terror group (see also 007's Spectre).
Swedish actor Ferguson certainly brings more to this and has more to do than past M:I women and her performance as Isla Faust keep you guessing about whether, as her name suggests, she's made a pact with the devil. That would be Syndicate boss Solomon Lane (Sean Harris).
Yes, like the leading man she's way too pretty to pass as a spy in the real world but her ambiguous character helps makes Rogue Nation the smartest M:I flick yet.
And yes Rogue Nation still offers tricky business with masks, a self-destructing message which does its bit for the vinyl revival and theme music which tastefully adheres to Lalo Schifrin's original.
Verdict: As good as this franchise gets
Cast: Tom Cruise, Simon Pegg, Jeremy Renner Alec Baldwin Director: Christopher McQuarrie
Rating: M (violence)
Running time: 132 mins