Sun Datao, the owner of a restaurant, is shot dead in front of his own establishment. The killer remains at large. Detective Tang Qi investigates and learns that Sun had previously cut and injured Sha Lianfu, a thug recently released from prison, in a jealous dispute over a woman. Sha is currently hospitalized in the city's No. 2 Hospital. Late one night, the stone cover of an underground heating pipe in the hospital ward is quietly lifted. Several shadowy figures emerge, secretly carrying Sha Lianfu away without anyone noticing.