Something very interesting happens about a third of the way through this odd comedy from debut directors Jarrad Paul and Andrew Mogel. We won’t say what. But the swivel transforms a largely formulaic romp into something that genuinely undermines lazy expectations. We’re not quite in Bobcat Goldthwait country, but we have pulled up into adjacent territory.

Jack Black plays a less socially successful variation on his stock character. Dan Landsman is helping organise the class reunion in a suburban corner of a drab flyover state. His fellow committee members ignore him during meetings and snub him when the time comes for home. At work, he sighs indulgently at a boss (the reliably first-class Jeffrey Tambor) who seems to think that technologies such as email and internet access are optional to the modern business. (Later on, as he begins to get to grips with the machines, a panicked Dan notes: “Oh no! He’s learned how to check his ‘recent calls’.”)

Dan hatches a plan. He will persuade Oliver Lawless (James Marsden), an actor currently appearing in a sun-cream commercial, to attend the reunion and will bask in the glory of his celebrity. On a trip to LA, Dan and Oliver get on reasonably well. Then the scheme begins to unravel.

This is the sort of film that expects to be watched through splayed fingers. Dan’s few moments of triumph are undercut by embarrassing disasters that push him towards total catastrophe. Oliver’s eventual disruptive return to his hometown spreads further mortifying mayhem about the region. It is to the credit of both Marden and Black that they manage to make two differently ghastly characters strangely compelling throughout.

Sadly, the film does trip over itself before taking a final stumble into conformity. Kathryn Hahn is wasted as Dan’s underdeveloped wife. The ending of the film could be the ending of any conventional comedy.

For all that, the film-makers are to be commended for venturing more than a few risky turns. Worth checking out.