Superficially, 'I Witness' sounds very promising: a thriller whose story mixes the battle of a union for recognition, a mass grave in Mexico and the mysterious vanishing of two American kids. But everyone speaks in that slick, snappy way you only seem to hear in film or TV, Jeff Daniels plays a human rights monitor as a self-righteous international detective, and Portia de Rossi is utterly ludicrous in her role, eye-candy disguised as an American trade envoy. More generally, the film lapses into portraying Mexico as a place where everything is utterly rotten, while the US government, although questioned, ultimately comes down on the right side in the rather ludicrous finale. Yet another criticism is that there's just too much action: for certain, there are plenty of worst offenders, but a drama with any real interest in Mexican assembly plants, or drug cartels, would follow a single story with more care, instead of decorating it with as many chases and gun fights as we get here. Ultimately, this is a film that doesn't seem to know what it wants to be: strip away the pretension to seriousness, and there's not much more than an underpowered version of something like the Jason Bourne films. It's a shame, because there's more than enough potential content in it's ideas to make a great movie.