I caught Mission: Impossible - Rogue Nation last week and, while a full review will appear in another publication at a later date, here are five initial thoughts about the enjoyable fifth entry in this almost 20-year-old franchise.

1. Christopher McQuarrie

Mission: Impossible's strength as a franchise is that it's not about Tom Cruise. It's actually about its directors. Every film has been a showcase for a different action auteur, from Brian De Palma (dutch tilt and deception) and Brad Bird (live-action cartoon) to JJ Abrams (blue filter, meta-script) and John Woo (slow-motion doves). They all bring their own style, which is partly why the series' cycle of one-upmanship delivers such entertaining results: the world impossible means different things to different people.

What does Christopher McQuarrie bring to the table? He's always been a writer (The Usual Suspects) more than a director, so while his visual fingerprints may not be everywhere - Mission: Impossible's director-as-star approach does have its weaknesses - his written signature certainly is. Hitchcock nods drive the largely retro plot, including red phone boxes on London's Great Windmill Street and a riff on The Man Who Knew Too Much in one superb opera-based assassination sequence; the introduction of Simon McBurney and Tom Hollander as British officials recall the labyrinthine intrigue of TV's Spooks (this is the first film since the original to be about espionage); but, most importantly, he conceives a set piece that is genuinely not possible for a human to overcome - a fact that gives this film's ludicrous action a surprisingly grounded sense of peril. This is also the first time since the original film that Cruise's super-agent Ethan Hunt (described as "the living manifestation of destiny" by Alec Baldwin's CIA boss) hasn't managed to achieve the impossible.

2. Joe Kraemer

The other key figure in any Mission: Impossible film is the composer. Or, to be more precise, Lalo Schifrin, whose signature theme from the original TV series has an almost Pavlovian effect upon people. Audiences hear it and they perch on the edge of their seat. Tom Cruise hears it and he starts dangling off the nearest skyscraper. After Danny Elfman's symphonic arrangement (Mission: Impossible) and Hans Zimmer's loud, unsubtle treatment (M:I-II), Michael Giacchino made M:I his own with two fantastic soundtracks that played with the theme in every way imaginable. It's to Joe Kraemer's credit, then, that he steps up to bat and knocks it out of the park. Relying more on the Lalo theme than any of the other composers, he restricts his whole orchestration to instruments from Schifrin's ensemble, delivering something that has the sound of Mission: Impossible, as well as the style and energy. (As well as the prolific bongo action, check out the vibraslap on "The Plan", echoing the same rhythm used by Lalo in "Jim on the Move" on the original show's soundtrack.)

3. Simon Pegg

Simon Pegg returns once more to the franchise as Ethan Hunt's phone-a-friend sidekick, Benji. His third appearance since M:I-III, Pegg's presence has been promoted from tech guy/comic relief to best mate/comic relief/active field agent, now getting to co-star in car chases and deliver such key exposition lines as "An anti-IMF?" to the camera. He wears the part well enough - I remember interviewing Pegg for Hot Fuzz years ago and him insisting quite adamantly that he was not "best friends" with Tom Cruise, how times change - but his recurring role, alongside the familiar faces of Jeremy Renner (as William Blandt, sorry "Brandt") and Ving Rhames (as hacker-supreme Luther Stickell) only emphasises the fact that the series has never given a proper second appearance to a female character. Mission: Impossible - Ghost Protocol was so promising because it ended with a team of agents, including Paula Patton's Jane Carter, ready to carry on the torch from Tom Cruise's Ethan Hunt. To see them all sidelined for more of the same male-heavy action, then, is a huge disappointment and a big flaw of the franchise, no matter how likeable Pegg is.

4. Tom Cruise

Tom Cruise may not be the star of the show, but he's a key instrument in its success: in an age of CGI spectacle, Tom embodies the jaw-dropping appeal of practical stunts, allowing himself to be blown up, hung off buildings and - now - strapped to a plane as it takes off, all to bring a new sense of excitement to the table. He's as sprightly now as he was two decades ago, while the occasional cragginess on his face brings a welcome mature edge to his IMF "legend". The problem, though, is that it only encourages the levelling-up of each set piece, which leaves Rogue Nation in the same situation as the previous film: not knowing when to stop, it keeps going and going, adding in too many set pieces. When it works, it rushes from one chase sequence to another - a daisy chain of thrills - but when it doesn't, the whole thing ends up 30 minutes too long. On the plus side, Tom's character has already been developed over the course of the previous films (the absence of any mention of Michelle Monaghan's wife after the fourth film is a shame), which means that more attention can be paid to the other players. That brings us nicely to…

5. Rebecca Ferguson

Forget the director. Forget Tom Cruise. The MVP of Rogue Nation is someone entirely different: Rebecca Ferguson. Who's that? If you haven't seen The White Queen, in which she played Elizabeth, you most likely won't know, but that only makes her turn in Rogue Nation even more effective. This is a star-making turn and she is sublime as Isla Faust, an enigmatic secret agent whose character is that she is an enigmatic secret agent. On the one hand, that means she's the stereotypical elusive female upon whom the largely male cast can project their various ideals. On the other hand, that means the hilariously (read: dreadfully) named Ilsa gets to use that against the largely male cast.

She has a sexual quality - McQuarrie's camera dives in for a butt shot very early on - and wears a stunning yellow dress to the opera, but even as she and Ethan abseil from the Vienna landmark together, there is no forced romantic subplot between them. The nearest she gets to being the movie's love interest is in her relationship with Sean Harris' villain, who is in charge of The Syndicate (the "anti-IMF"), and is susceptible to her feminine wiles. One scene with Simon McBurney's MI5 head, meanwhile, gives her the kind of double-agent depth that could power a whole season of Spooks. The fact that she can kick ass and saves our hero's life (rather than the other way around) without it being a big deal, makes her a fantastic asset to the Mission: Impossible franchise. The fact that she will almost certainly not return in the next sequel, though, only makes you wish for more screen time devoted to her - say, the whole of M:I-6. That, you sense, really would be an impossible mission for the franchise.