Star Jake Johnson told the media about how mumblecore godfather Joe Swanberg isn't as interested in plot as he is in the freewheeling improv performance style he's become known for.

If you haven't liked Swanberg's work until now (Drinking Buddies, Happy Christmas), that won't be the best news you could hear, because the trailer makes Digging For Fire look like Swanberg's signature style but with an actual story that has a little bit of mystery.

Lee (Rosemarie) and Tim (Johnson) are house-sitting a very cool place in the Hollywood Hills when Tim finds an animal bone and an ancient, rusty handgun in the dirt near the house.

Lee takes their infant son off to her mothers' place so she can go and meet a friend for a girl's night out, making Tim promise he'll get the family taxes done that weekend. Instead, Tim has a bunch of buddies over, drinks beer, cooks burgers, talks big about his find and soon they're all digging for more clues.

Meanwhile Lee is frustrated in her attempt to get her friend to come out with her so she goes out alone, bumping into a rumpled and charming Englishman (Orlando Bloom) and feeling an attraction neither can deny.

Tim himself has warmed to a girl, Max (Brie Larson), one of his oversexed friends bought over the previous night, particularly when she shows up the next day to help him dig, intrigued by the story.

It's all held together by a deceptively well-juggled series of subplots and connections, but the whole thing just doesn't go anywhere much. What seems to be developing into a tale of infidelity peters out quite a bit more chastely than you imagine it will, and all the soul searching going on might make you wonder when these privileged white urbanites will ever get over themselves.

It's a common theme to Swanberg's movies, and it isn't helped by the fact that so many turns in the story are picked up and then abandoned – Swanberg indeed seems to have no interest in narrative.

The mystery of the gun and bone (a collection that's added to as they keep digging) is just one plot strand that isn't concluded. Lee meets a woman on the beach looking at Saturn through a telescope. An old man from nearby visits and hints at a dark incident that might have led to the buried gun. One of Tim's close friends from his pack (Sam Rockwell) ends up throwing a tantrum and storming out of the house. And little of it represents the genesis or closure of any particular story strand.

The trailer will make you think Digging For Fire is a zany urban comedy. There's a great cast and the performances are authentic – as long as you like Swanberg's style where he gives the actors the direction of the scene and has them make up their own dialogue.

If you hated that kind of thing in Happy Christmas and Drinking Buddies, it isn't nearly as grating here, but the movie promises a lot more story than there actually is.