What's great about film festivals: I Served the King of England started late and I had to leave without waiting to attend director Jiří Menzel's Q&A (not that Q&A's are ever really worthwhile), but I as I snuck out of the theater, I got to see him, from a distance of about 8 inches as we squeezed path each other in a hallway.

I must confess to my shame that I'd never seen any of Menzel's films before, not even his much-loved Closely Watched Trains (though I have an idea of when that particular gap in my education will be filled), and therefore I feel ill-equipped to discuss his latest film, to say the least. But if I can't slot I Served the King (adapted from the same novelist as Closely Watched Trains) into any greater thesis about the director's development, or into the development of the Czech cinema as a whole, at least I know that it's ridiculously funny.

Moreover, it is a ridiculously funny silent film, for although it has dialogue and music and sound effects, those things are used sparingly, and the gags are all structured after the fashion of a 1920s slapstick comedy. Lest we think this is an accident, Menzel tips his hand rather early: one of the first scenes in the film is presented as a literal silent movie, in black-and-white with intertitles, the film itself faded and scratched to appear older.

The film opens in the mid-1960s, as Jan Díte (Oldrich Kaiser) is released from prison, observing in narration that he was meant to serve 15 years, but thanks to a general amnesty, was released after only 14 years and 9 months, and something about the syntax of the gag and the way it is narrated over the action feels very 1920s-style. There is at least the possibility that I am too married to my thesis.

But then there's the face of Díte as a young man, as played by Ivan Barnev, and he gives me a much better leg to stand on. Because Barnev looks inexplicably similar to the bastard son of a union between Charlie Chaplin and Harpo Marx, with the former's physical bearing a tendency towards twitchy little details of performance wedded to the latter's sly, licentious grin and playfully expressive face. In effect, Barnev gives a silent performance even when he has dialogue (which is infrequent, actually): he communicates everything we need to know in tiny pieces of physical acting, whether it's the look on his face or simply the way he walks though a room

The film revolves around the older Díte as he settles into a government-mandated job helping to clean out the abandoned German settlements on the border (a relic of the time before the war when the two countries had a friendly and open policy), and his subsequent memories of the road that took him from selling hot dogs at the train station to becoming a millionaire (and pointedly not serving the king of England, although he is given a medal by the emperor of Ethiopia). It's a funny and charming take on the basic Horatio Alger model, deepened by the filmmakers' invocations of the history of cinema and the national character of Czechoslovakia.

And after a point, the movie pulls the rug from under our feet, and even while on its face it's still funny and chipper, there's a dark core pulsing balefully. This treads into spoiler territory: when the German government starts to annex portions of the country, Díte decides not to join in the solidarity or resistance movements of his co-workers and neighbors, but willingly - joyfully! - becomes a collaborator and falls in love with a German woman, and does what he can to turn a nice profit from his efforts.

The shift from playful comedy to this strange hybrid of the comic and the upsetting is managed perfectly, and the new moral tone the film adopts is neither preaching nor obvious: indeed, the movie is very sly about the awful implications of this plot, up until the final moments of the film, in which old Díte surrounds himself with mirrors, mirrors which we have been told are thought to hold German ghosts, and he looks around at who he has become. It's the one and only truly sad moment in the film, but it doesn't feel anything other than inevitable. The whole film has been about remembering the past; it is only in the final moments that the callow youth at its center finally has the strength to confront the past.