Something about the trailer pointed to a grand mystery, an undercurrent of danger and fear in its depiction of a family holidaying in an idyllic landscape. The results is a bit more prosaic and not as climatic as I'd hoped, but however less-than-satisfying the narrative turned out to be, the tone of menace by director Michael Franco is still well wrought.

Neil (Tim Roth), Alice (Charlotte Gainsbourg) and what appears to be their kids Colin (Samuel Bottomley) and Alexa (Albertine Kotting McMillan) are obviously wealthy if the opulence of the holiday they're enjoying in Greece or Spain (it actually turns out to be Mexican 70s tourist mecca Acapulco) is anything to go by, lounging by the pool and being waited on by dedicated staff in their luxurious villa overlooking the bejewelled ocean from the top of a cliff.

Everyone else is enjoying themselves but despite his surroundings, Neil appears to be miserable. Then, a phone call shatters the peace anyway – Alice's mother has fallen sick back in the UK and the family quickly bundle themselves together to fly home in time, but they get the fateful call that she's died at the airport preparing to leave.

Alice and the kids are almost inconsolable and Neil, as stone-faced as before, tells them he's accidentally left his passport back at the hotel and that he'll catch up with them on the next flight.

Instead, he goes back to town with a dodgy looking cab driver and checks himself into a seedy dive, spending his days sitting at the beachfront bar drinking beer and ignoring Alice's increasingly frantic calls and texts demanding to know where he is.

He gets together with Berenice (Iazua Larios), a vivacious young woman who owns a store near the beach, and even when his belongings are stolen from his hotel and he witnesses what seems to be a gang-related shooting on the beach, Neil barely raises an eyebrow.

From there it turns surreal. Alice shows up back in Acapulco weeks later to confront Neil about why he didn't come home and ignored her pleas to contact him and help deal with their mother's death.

Yes, their mother. In a weird twist I don't think was intended, Neil and Alice aren't married at all, they're brother and sister, Neil's always just been close to Colin and Alexa (Alice's kids). When he first starts hitting on Berenice he tells her he's not married and the kids aren't his, but I thought it was just a ruse so she'd sleep with him. Did Franco (directing his own script) intend for me to not realise he was telling the truth for so long?

I wondered if there was a throwaway comment or clue early that told the audience the pair were actually brother and sister and I missed it, or if the whole reveal was mishandled.

Anyway, as Alice is leaving, the dodgy cab driver Neil's befriended shows his true intentions and a tragedy results. Gradually, after going to a hellhole Mexican prison, interacting with the family lawyer and the two kids about getting him freed and who'll control the family's vast business interests, it emerges that Neil wanted to blow his life completely up – and the reason why is a bit less dramatic than what his actions have suggested.

The cinematography does justice to the locales and there's a successful Hitchcockian sense of something sinister unfolding, but as soon as Neil is thrown in jail it started to feel a bit like the script was running out of ideas.

I'm also bemused by all the fawning I've read over Roth's performance when he does absolutely nothing. Whenever an actor portrays a character completely devoid of emotion or rippled by inexpressiveness (see plenty of roles by Ryan Gosling), it's pretty common for critics to mistake not barely lifting a finger with good acting.