In the northern coal mines of China, one expects to find poor migrant workers toiling away, enduring dangerous, backbreaking labor so that they can send whatever little money they make to their families back home. But beneath the ground, the depths of human nature can be revealed when greed and desperation drive some miners to unthinkable actions. "Blind Shaft" is the bleak and unflinching story of two con men whose partnership is irreparably shattered when one experiences a return of conscience after years of living in the dark.

Song Jinming and Tang Zhaoyang are two migrant workers who have created an elaborate extortion scheme allowing them to earn fast money without enduring the hard labor of the mines. First, the criminals secure a mining job for three workers in a remote (often illegally-operated) mine. They then offer the third position to a random person seeking work so long as the person agrees to pretend to be one of their relatives. While negotiating the contract with the mine’s management, the two ensure that substantial compensation is provided if one of the three are to die in a mining accident.

The two men then murder the “relative” underground and make the incident appear as a typical mining accident. The criminals proceed to collect the compensation money on behalf of the deceased relative’s “family” and continue on to the next mine to repeat the profitable scheme again. The film begins with the pair murdering one victim before sending the compensation money to their own families (instead of the victim's) back home. The system seems to be working smoothly until the abrupt and unexpected return of Song’s conscience in the form of guilt and morality.

What helps initiate this return is the innocence of their newest victim, Yuan Fengming. Yuan is a smart but timid 16 year-old high school drop-out who wants to make money to pay for his sister’s secondary education. Yuan’s cherub face, bright attitude, and good heart reflect the naiveté of youth itself. Yuan remains blissfully unaware of the evil and danger that await him when Song and Tang recruit him from a local train station.

While Song carefully watches Yuan study in hopes of one day returning to school, borrowing money to give to a beggar on the street, and obediently following orders, he begins to suspect that the victim at the beginning of the film may very well be Yuan’s father. This realization does not sit well on Song’s newly returned conscience, and the more he listens to an oblivious Yuan talk about his father, the more the guilt he had once buried far underground begins to surface.

This guilt drives Song to treat Yuan harshly at first, perhaps with the hope that Yuan will abandon the pair and seek work elsewhere. However, Yuan proves stronger than expected, his will to provide for his sister serving as the base for this inner strength. Tang, who shares the exact same motive—earning money for his family—is ironically Yuan’s polar opposite. Although he is more gentle and personable towards the boy, his affection proves merely surface-deep. Unlike Yuan, Tang is not restrained by morals, values, or conscience and thus is able to resort to unspeakable and vile actions to achieve the same goals.

Tang is a fairly one-dimensional character who does not develop or change during the course of the film. In contrast, Song witnesses an internal transformation that forces him to confront his own demons of the past and make a moral decision. The ethical dilemma Song faces involves the question of whether to save the boy or continue on his current path of sin. As the film goes on, Song, perhaps subconsciously, realizes that saving the boy could be his only chance for true redemption.

Though in the end both Song and Tang endure the ultimate punishment for their sins, it is assumed that Song’s choice to betray his wicked partner and save the young boy is the key to his own salvation in the afterlife. In contrast, Tang will probably remain deep underground, along with all the skeletons he’s left behind.