Considering both the action-comedy and Tom Cruise were two of the more successful parts of 1980s cinema, it’s surprising that Cruise hasn’t starred in more of them. In fact, aside from his supporting role in Tropic Thunder and a cameo in the third Austin Powers, Knight and Day marks Cruise’s first comedy role since Jerry Maguire (although of course there are some who would claim that Eyes Wide Shut and Vanilla Sky had a fair amount of unintentional comedy in them). So it’s highly likely that audiences will spend a fair amount of time when watching Knight and Day wondering what exactly attracted him to this script.

Reuniting him with Vanilla Sky co-star Cameron Diaz (who is thankfully much less irritating here than her hysterical turn in that movie), Knight and Day charts the whacky scrapes that happen to Diaz as tom-boyish singleton June Havens after she accidentally gets on a flight with Cruise’s loose cannon secret agent Roy Miller and then ends up having to go on the run with him in order to keep herself alive as well as stop a marvellous MacGuffin (and the genius behind it) from falling into the wrong hands.

Clearly the stars and the director James Mangold (who has proved himself capable of handling both award-winning dramas with Walk The Line and Girl, Interrupted, as well as rather less distinguished fare like Identity and 3.10 to Yuma) are punching below their weight with this movie – the globe-trotting action rom-com is something that’s been done better before. The uninspired nature of the script starts with its title (Knights feature in a couple of different guises, but not in a prominent enough way to make the title actually seem as clever as it wants to be) and doesn’t stop there. Also for a film so reliant on special effects, it’s surprising how cheap and dated many of them look, particularly the film’s over-reliance on unconvincing green screen shots. However, despite all this, Knight and Day is a difficult film to dislike.

What mostly makes the film interesting is the presence of the two leads. Cruise does his usual charming thing, and it must be said that he does it well, but owing to his highly publicised private life it’s no longer easy to take this at face value, which adds a layer of suspicion to the actions of Miller, perfectly fitting for a character who is meant to straddle the line between paranoid and heroic. Diaz on the other hand is not only her pleasantly warm and amusing self, but it appears has actually decided to let herself age gracefully and naturally, which is admirable considering both the usual standards of beauty for women in Hollywood and the fact she launched her career based entirely on her looks, and this in turn makes June more relatable and likeable than if she had been played by one of the many of the other actresses who could have filled this part.

A strong supporting cast also helps matters, even if the casting is pretty uninspired – of course Peter Sarsgaard is going to be playing someone shifty and untrustworthy, and Paul Dano will turn in a weird, nerdy performance, fortunately they’re pretty much just left to get on with what they’re good at. There’s also a long list of exotic locations straight out of a Bond movie to look at, and a few nice running gags such as where a series of ever more ludicrous action scenes are merely seen as glimpses as a character comes in and out of consciousness (which could well have been a practical necessity in order to save money from the effects budget, but ends up being among the film’s highlights).

It’s hard to begrudge Knight and Day its existence, even when it so much of it looks so shoddy when the amount that was spent to make the film is considered. There’s nothing about the film that could really be seen as being offensive, at its best there is something goofily likeable about it, whereas at its worst (which, it must be said, is a fair chunk of the film’s running time) it’s merely unremarkably forgettable.