We do not know their names, their faces, their families or their personal stories. Nobody really does. They are strangers, in a faraway land, doing the unthinkable. In Japan they have a name: The Fukushima 50. A coterie of nuclear plant employees - some reports indicate 50, others suggest four working rotations of 50 - who stayed behind while 700 of their co-workers were evacuated from the stricken Fukushima-Daiichi facility on the Japanese coast.

Five have been killed. Two are missing. Twenty-one have been injured in a struggle where, in the words of Japan's Prime Minister Naoto Kan, "retreat is unthinkable." The men understand the stakes. They know there is no turning back. One worker told a departing colleague he was prepared to die - that it was his job. Another informed his wife he wouldn't be coming home anytime soon.