In polished Brit horror flick Eden Lake, a young couple, primary school teacher Jenny (Kelly Reilly) and boyfriend Steve (Michael Fassbender) speed out of London one weekend with Steve promising partner Jen that he has found this wonderful spot by a beautiful secluded lake.

Steve is looking for a weekend out of the ordinary and quality time with his beloved. They've been getting along fine, so much so, he's hoping to pop the important question if he gets the right moment.

They stop firstly at a local hostelry which should of course be idyllic but their peace is spoilt by noisy ill-educated locals where parents meter out a swift slap to misbehaving children. They put this down as a one-off and next morning are heading for their idyll by the lake.

An oblique bad omen is of course totally ignored. The sat-nav politely but firmly advises them 'that they should turn round and go back' ; naturally such delicate warnings are completely ignored. Don't say I didn't warn you, should retort the Tom Tom.

The two of them reach their idyll and sunbathe in peaceful surroundings, leaving you wondering where any menace is going to come from. Will there be some horrible monster lurking in the lake or a passing hungry bear in the woods?

Proving though that if you go down to the woods today, you're sure for a big surprise, their peace is shattered when a group of local teen rowdies career up to the water's edge on their BMX's, send a swotty kid packing and then proceed to drink, smoke and hurl dirty comments towards Jenny as they play their ghetto blaster.

Jen wisely suggests she and Steve move, it's a big lake, they're sure to find another beauty spot but macho Steve retorts 'we were here first' and confronts the yobs about their behaviour. Bad move.

The kids take the admonishment badly and in subsequent hours and into the next day, the mood is going to turn far worse especially when Steve confronts the group again after they've joyridden his 4 x 4.

From there, you've got something akin to Lord of the Flies as a pack mentality swiftly turns a couple into the hunted and sucks the local teenagers into a spiral of vengeance goaded by a particularly vicious gangleader (Jack O'Connell).

Eden Lake ought to do well. It holds levels of suspense well, the set-up is credible and it's a decently polished Brit film where interestingly those perpetrating the horror are all too believably the kind of young oiks who hang around on street corners that you cross the road to avoid.

Debut director James Watkins, who also wrote the film and worked on My Little Eye brings to the picture a form of heightened realism which for the most part works, even though there's the odd moment when an audience will be universally caught in disbelief. When Jenny for example, reaches a construction hut, the kids search all the way round and as the camera pans away, we see miraculously she's climbed onto the roof and done so without being seen when a better bet would have been for the director to have a shot of Jen hiding under the hut. Jen scrambling under in a few seconds we could have believed.

There's some reasonable acting on show though. Kelly Reilly is fairly hot as an actress at the moment and she does well in a gutsy role here. Thomas Turgoose also turns in a decent cameo as a member of the gang starring in what is a darker film, than the ones he's so far been used to, under the tutelage of Shane Meadows. Michael Fassbender also does well in the role of Steve.

The film heads towards a dark haunting denouement - do bear in mind this is no wholesome chick flick but its got bags of suspense and presents a believable cross-section of British society. Overall a decent effort.