In A BRIDGE OVER THE RIVER, we meet Jesus Manuel Lorenzo Moya - Lency to his friends and family - a veritable genius when it comes to designing, building, and repairing anything mechanical.

Lency's home in the remote Escambray mountains is an unassuming affair surrounded by woods. But enter his workshop and you're faced with an extraordinary array of gear: a shelf full of old clocks; a homemade metal lathe that Lency uses to mill his own screws and bolts; dozens and dozens of wrenches; a drafting table for his many plans. There's even a homemade forge in which Lency fires iron, using a carburetor nozzle connected to a windshield wiper motor to control the airflow. "It's not an industrial part that has to be made in China or Japan. I made it here myself. And it works," he explains.

The documentary starts off showcasing some of Lency's relatively modest efforts - constructing a part for a piece of agricultural machinery and adapting a distributor cap for a neighbour who was sold the wrong part. But soon we are introduced to work that reveals the true scope of his genius. There's the motor-powered hang-glider he built (but that nobody wants to fly, because it could be considered a politically suspicious activity). Then there are the tractors - all three of them - that are almost entirely of his own design and construction, complete with exhaust systems made from old water pipes. And finally, the piece de resistance: a homemade hydro-electric power plant that generated six kilowatts of electricity and powered Lency's and his neighbors' homes, until electricity came to the village and parts from the plant were pilfered for other projects.

While he could probably make more money if he moved to the city, Lency is perfectly content with his life: living in a beautiful setting, helping his neighbors, and giving free rein to his creativity.