Searching

There were some real gems tucked away in Sundance's Next section this year that could just as easily have featured in the main competition, including this whip-smart debut thriller from Aneesh Chaganty (originally entitled Search). One of those rare occasions when a great concept is borne out in execution, this is the story of a disappearance, as viewed by us looking out at the world from behind the computer monitor of distraught but determined dad David (John Cho).

In an economical but surprisingly poignant set-up, David's family are introduced to us via a skip through social media, involving emails, photos and the like down the years, immediately cluing us in to David's status as a single dad who has loved and lost, and his teenage daughter Margot (Michelle La), in addition to, crucially, investing us emotionally in their relationship. Throughout the film, Chagnaty strikes an excellent balance of the banal and the important, from those key life images to conversations about throwing out the rubbish. The picture is of a normal household, until one night David misses a couple of calls from his daughter after an early night. The rhythm of their household is such that her absence isn't immediately noticed, although the fact she forgot her laptop does seem odd.

Soon, however, David realises something is wrong and on when he discovers his girl has been lying to him about something, albeit reasonably innocuous, alarm bells start to ring. As he contacts the local police and Detective Rosemary Vick (Debra Messing) takes up the case, he also begins to dig around in Margot's virtual life online, phoning her 'friends', and trying to crack various passwords, his panic level ratcheting up all the time.

The film - co-written by Sev Ohanian - is not just clever in the way that it uses familiar programs and the Windows and Apple Mac environments but also in the way it triggers familiar emotions. They home in on the sort of nightmare scenario feared by parents, showing the way that adults can appear to be hyper-connected to their children and yet still know only a small fraction of what they are actually getting up to when they connect to the internet. What's crucial here, however, is the balanced way this is depicted, it's a cold drip of fear rather than a hysterical rant against the machines. As the tension begins to mount - and there is barely a moment of the run time that isn't taut as a singing wire - Chagnaty stays true to his concept and includes some lovely 'real life' touches, such as buffering and a chat rant that is deleted rather than sent. Somehow they also find room for social commentary - skewering the 24-hour news cycle and the way that 'emotions' may not be all they seem.

Cho, so good in last year's Columbus, is a thoughtful actor who is also able to convey thought processes beyond the dialogue - a skill that makes him perfect for a role that often has his face filling the frame of a screen. The concept may be high but it's the smart execution that really makes this film work, as the thriller elements unfold in unsurprising ways, both in the way they are depicted using various computer programs and in terms of plot surprise. In five years time, if you Google, 'Great films using the internet as a plot device', I'd expect this to be returned as the top hit.