No. 17

It starts with a suicide bomb, but this engrossing documentary has little to do with the Israeli-Palestinian conflict. No. 17 is a real-life mystery, filmmaker David Ofek's attempt to identify the final victim of a bus that exploded on the outskirts of Tel Aviv.

The other 16 victims were quickly accounted for, but the body of "No. 17" had disintegrated beyond the ability of even forensic scientists to identify him. No family or friends reported him missing. And so, with only a few sketchy details to go on—the man had packed a tent in his luggage—and with no certainty that his investigation will produce No. 17's name, Ofek uses the camera to collect evidence.

One survivor flashes his ticket and jokes darkly, "I wonder if the bus company will refund my money. The trip was not completed, after all." An Israeli official in charge of processing unidentified bodies adds, more philosophically: "Sometimes we live anonymously and are buried anonymously."

Perhaps, but one clue in this remarkable documentary proves essential—both to unraveling the mystery and to underscoring the film's theme that even the most disregarded among us leave a trace: According to witnesses, No. 17's most distinguishing feature was his smile.