Cambridge Film Festival officially opened last night, kicking off with postmodernist French crime caper The Kidnapping of Michel Houllebecq and Woody Allen’s 1920s romantic comedy Magic in the Moonlight – both showing again today.

Houllebecq, France’s most famous living writer, briefly disappeared in 2011, sparking intense media speculation – and rumours that he had been kidnapped. The Kidnapping of Michel Houllebecq is a fictional retelling of what could have happened during those mysterious weeks.

Created using a 20 page list of scenarios, actions and conflicts, copious bottles of wine and hundreds of hours of unscripted footage, the film, which stars the real writer Michel Houllebecq as himself, is a curiously postmodernist blend of Being John Malkovich, Coffee & Cigarettes and The Only Way is Essex.

… It sounds like a car crash, but somehow, it works.

Petulant, charismatic Houllebecq chain-smokes and bickers his way through the film, retaining an identical air of ennui whether debating the merits of Mozart with friends or complaining to his kidnappers that he can’t eat a sandwich without at least two glasses of wine.

Much of the film’s comedy is drawn from Houllebecq’s ongoing attempts to create low-key conflict and the bemused sincerity of his captors. The huge, Krav Maga-fighting, slightly starstruck kidnappers fuss over Houllebecq’s welfare, seeking his advice on creative writing and refusing his pleas for a lighter with pained, parental reluctance.

When he points out that letting him see their faces seems to him a “bad sign,” they chime in with appalled denials, reassuring him that it will soon be over, but “in a good way.”

Like his muse, Director Guillaume Nicloux is an impish troublemaker, who spent much of the post-screening Q&A pulling his chair uncomfortably close to audience members to be more “intimate” or embarrassing his translator with risqué jokes that she’d have to explain in English.

But while Houllebecq’s brand of mischief is as about as dry and Gallic as a Muscadet, Nicloux treats his subject with a lightness of touch that transforms a film about a depressed hostage into a joyfully irreverent farce.

Compared with this accomplished comedy, Woody Allen’s Magic in the Moonlight – itself an attempt at joyful, irreverent farce – falls flat.

Set in 1920s Côte d’Azur, the story follows an arrogant, atheistic magician tasked with unmasking a fraudulent mystic. Instead, in typical rom-com style, he finds his worldview challenged in ways he didn’t expect.

Visually, it’s perfect. Darius Khonji’s gorgeous cinematography and Sonia Grande’s impeccable costume design combine in a breathtaking vision of the period. But the awkward, exposition-laden dialogue, shallow characterisations and daft plot twists gave it the feel of a high-budget episode of Poirot, while a glaring lack of chemistry between leads Colin Firth and Emma Stone make the storyline hard to swallow.

Allen is best when he’s doing Allen: sharp, witty and ironic. In Magic in the Moonlight, he tries for the opposite: sentimental, optimistic sincerity. For the most part, it fails.

The best characters in the film are at the fringes: Brice (Hamish Linklater), the puppy-eyed suitor who follows Sophie (Stone) around with a ukelele, relentlessly professing his love, and George (Jeremy Shamos), a skeptical doctor who speaks with Allen’s voice and has all the best lines.

In fact, it’s George that inadvertently sums up why the film’s central theme, how even an snarky misanthrope can change his ways and learn to love life, is such a bad choice for Allen’s breed of comedy.

“A very, very unhappy man,” he says of Firth’s character, Stanley. Then, drawing a laugh from the whole audience: “I like him!”