You have to feel some sympathy for the folk behind the third film in this faltering family franchise. The death of Mickey Rooney and Robin Williams, regular cast members, during post-production ensured that a certain melancholy would hang over Secret of the Tomb. On the other hand, the filmmakers now have a handy excuse for the mirthless silence set to spread through the world's cinemas.

This really is a hopeless project that makes little of the original film’s few good ideas and adds no new ones worth enduring. As all US films must be about fathers and their sons, Ben Stiller’s harassed museum guard is now juggling the nocturnal management of possessed artefacts with daytime supervision of a mildly rebellious teenage son.

When the ancient tablet that makes the exhibits live goes on the blink, they all must travel to the British Museum for some sort of recharge. Cue the Queen's Life Guards. Cue Tower Bridge. Cue Trafalgar Square. Cue London Calling by the Clash. Hang on. Can Joe Strummer and the chaps really have imagined that their apocalyptic stomper would, one day, become the accompaniment to every second cliched montage of the city?

So dull is the film that such irrelevant ponderings keep troubling the brain. Did Dick Van Dyke, back for a third time, pass his notorious cockney accent from Mary Poppins on to an uncharacteristically hopeless Rebel Wilson? What will Greek audiences make of the animated Elgin Marbles sequence and the script's eventual decision that the Egyptian tablet belongs with its fellow post-colonial captives in Bloomsbury (rather than in, say, Egypt)? What do we make of a film whose best joke involves the mispronunciation of Hugh Jackman's name?

They even manage to bungle a glaring opportunity to bid a poignant farewell to Robin Williams. Okay, that may have been a bit tasteless, but it’s not as if the rest of the film slips past the palate like fine caviar.

Let this be an end to it.