Trapped in the dilemma of delayed graduation, archaeological Ph.D. student Zhou Shi takes over the campus lost and found office, determined to trace the origins of various unclaimed artifacts using field archaeology's micro-trace analysis method. Facing the harsh questioning of his fellow students and the stern scrutiny of his mentor, he joins hands with assistant Lin Xiaoman to peel back the layers under the microscope, breaking through heavy resistance with subtle physical evidence such as mud and pollen. However, when a decades-old sealed exploration object sees the light of day, can Zhou Shi withstand the prejudice, use this niche special skill to untangle the mysteries of the years, and return memories to their rightful owners?