‘Old Stone’ shows a cab driver’s costly compassion

Lao Shi (an outstanding Chen Gang) is a cab driver in a modest Chinese town who accidentally runs his vehicle into a motorcyclist when a drunken passenger grabs his arm.

Instead of fleeing, he loads the victim into his cab and takes him to the emergency room, even — trusting soul — paying the bill.

For the filmmaker, the flawed system that results in Lao Shi’s undoing isn’t simply a matter of institutional indifference — it has deep and extensive roots in this society.

Chinese law doesn’t exactly promote compassionate behavior — a driver who kills someone may suffer fewer consequences than one who severely injures a victim, and thus can be held liable for years and years of medical costs.

The authorities — the police, the insurance company, and his employer — immediately begin second-guessing Lao Shi’s behavior.

For a time he’s able to hide the situation from his wife (played by the film’s producer, Nai An), who hopes to use their savings to expand her day-care business.

While this final segment is the least satisfying, it’s impossible not to be impressed with what Ma accomplishes in the film’s brisk 80 minutes.