One of the benefits of attending the London Film Festival is the occasional appearance by an actor or film-maker whose work I have found pleasing.

By ‘appearance’, I don’t mean those occasions when a red carpet is called for. The people who stand on the wrong side of metal fencing for hours hoping to catch a glimpse of Kia-Ora Knightley looking skeletal, or wishing that Tom Cruise might have an inane conversation using their mobile phone should be locked up in a concentration camp.

No, the kinds of appearances I mean are such things as Q & A sessions by people whose opinion you actually care about (as an aside, I stood in the same queue yesterday as Stephen Frears (The Queen, Tamara Drewe) and Jim Broadbent which I’m ashamed to say provided a nice moment, but I digress).

One of these took place today with the great John Sayles, whose film Amigo we had just watched.

John Sayles is a bit of a legend. Like John Cassavetes before him, Sayles doesn’t do compromise; instead he does that thing so few Hollywood film-makers even bother with – he treats his audience with a modicum of intelligence.

Sayles is probably best known for his fantastic baseball drama Eight Men Out and Lone Star, his dark, dark murder mystery. Because he doesn’t serve up schlock, Sayles naturally struggles to find the funding he needs to get his projects off the ground. So it was with a sense of genuine anticipation that I sat down to watch Amigo.

The film is set in and around Luzon in the Philippines at the turn of the 20th Century. The Spanish colonialists have been defeated by an America which is starting to stretch its superpower muscles.

For the ordinary villagers, the only thing that has changed is that one colonial power has been swapped for another. For some, the prospect of having their country stamped on by another invading force is too much and they take to the hills to become insurgents.

For the American soldiers on the ground, they see themselves as liberators who must win “hearts and minds” and impose democracy on the Filipinos … whether they want it or not.

Sound familiar? Well, it must be said that Sayles trowels it on pretty heavy-handedly when it comes to the Iraq symbolism.

His use of irony is also rather thick. In one scene, Lt Compton (Gareth Dillahunt), when asked why elections are being held in the village they are occupying says “we in America believe the beliefs of the people are sacred”, missing the point that precisely none of the villagers would want to be sharing their personal space with Yanks given half a chance.

But it’s in the character conflict where Amigo really shines. With the exception of Chris Cooper’s racist Col Hardacre, the characters are given enough depth to make them rich and believable figures, most especially Joel Torre’s village ‘head man’ who finds himself in an impossible position, caught between maintaining his people’s safety by working with the Americans and being seen as a collaborator by the guerillas.

This is a period of history which has almost totally been overlooked by western film-makers – indeed, the US-Philippines war is a virtual footnote, I sure as hell had no knowledge of it – so Sayles must be congratulated for shining a light on an episode which is sadly all too pertinent today.

John Sayles is somewhat of an indie darling, an adjective that might soon apply to Aaron Katz if Cold Weather is anything to go by.

Katz has made a name for himself by being included in that crop of film-makers (Lynn Shelton, Mark Duplass) responsible for the mumblecore movement in the US. The staples of mumblecore tend to be the following: twenty-something characters, largely improvised dialogue and plots that are about as paper-thin as Tony Blair’s conscience.

With Cold Weather, Katz has taken something of a departure from his previous two films Dance Party USA and Quiet City by employing genre film-making, namely the mystery thriller.

Doug is a college drop-out who has left Chicago and moved back in with his sister Gail in Portland. He gets a job at an ice-packing plant and befriends Carlos, a co-worker and part-time DJ. Doug introduces Carlos to The Adventures of Sherlock Holmes and soon the pair are investigating the mysterious disappearance of Doug’s ex-girlfriend Rachel, who has recently arrived in town.

A dollop of Hitchock here and a serving of the Coens there help to make Cold Weather an intriguing mystery with a couple of genuinely nail-biting sequences towards the end. However, you can take man out of mumblecore, but you can’t take the mumblecore out of the man and Katz never strays for very long away from the film’s heart, specifically the relationship between Doug and Gail.

This is probably the best portrayal of siblings I’ve seen on screen since 2000’s You Can Count On Me. Everything, be it a shared memory over an old mixtape or a pointless whale-watching trip, gives the impression these two characters have been in each other’s lives for ever and full credit must go to Cris Lankenau and Trieste Kelly Dunn for totally selling it to us.

If wham-bam explosions gets you off then don’t bother with Cold Weather, but if you appreciate a film that lets dialogue set the mood and isn’t afraid to let characters be genuine human beings then this is for you.