During the reign of Renzong in the Northern Song Dynasty, Su Renqiu, the youngest "Golden Thread Master" in Bianjing Embroidery Workshop, defended an old neighbor woman and unexpectedly showed his amazing ability to deduce the facts of the case through embroidery patterns and silk thread traces. Starting from the half piece of blood embroidery fished out of the dye vat in the embroidery workshop, she was involved in twelve unsolved cases, including the "Serial Disappearance of Embroidery Lady", "Poison Murder Case in Dyeing Workshop", and "River Lamp Drowning Case". Each case is closely related to the "Su Family Embroidery Book Stolen Murder Case" twenty years ago. Hidden detective Pei Yan pretends to be an apprentice in an embroidery workshop in order to track down an old case. As they peel off the cocoons, they discover that the threads of all the murders actually lead to the "Wanbao Pavilion" that controls half of Bianjing's business. The head of the embroidery workshop, whom Su Renqiu regards as his sister, is the key figure who led to the destruction of the Su family...
