Inside the Binyang Central Cave at the Longmen Grottoes in Central China's Henan province, a researcher from the Longmen Grottoes Research Institute holds a small 3D-printed fragment against a weathered stone wall. For a moment, nothing happens. Then the piece clicks into place, its curve fitting perfectly into a shallow groove carved 15 centuries ago.
The data show a 93.3 percent match.
"It was the most unforgettable moment," recalls Chen Yi, the documentary filmmaker who witnessed the discovery. "Completely unexpected. We found the face of Emperor Xiaowen."
In the past, it could take cultural heritage workers years to relocate a single Buddha head to its original position. This time, the documentary team helped accelerate the process, completing it in just 14 months.
"The key was finding the right method," Chen says.
That breakthrough and the years of detective work behind it lie at the heart of Chen's new documentary, How I Miss "Her", which aired on China Central Television's documentary channel on Sunday.
The film traces the century-long odyssey of the Emperor and Empress Paying Homage to the Buddha, a pair of carved stone reliefs from the Northern Wei Dynasty (386-534), regarded as masterpieces of Chinese Buddhist cave art.
In the 1930s, the reliefs were violently dismantled.
Working on orders from overseas buyers, a Beijing antiquities dealer named Yue Bin organized the systematic chiseling of the two panels into more than 6,000 fragments. Around 4,000 pieces made their way to the United States, split between the Metropolitan Museum of Art in New York and the Nelson-Atkins Museum of Art in Kansas City, Missouri. The remaining 2,300 or so were kept in Longmen's storerooms.
No one could determine with certainty which fragments were authentic. Looters had mixed genuine pieces with fakes to inflate prices, according to historical records of Yue Bin's confession cited in the film.
Abroad, the fragments were also subjected to questionable restoration practices. At the Nelson-Atkins Museum of Art, then-curator Laurence Sickman — whose teacher, Langdon Warner, remains controversial for removing murals from the Dunhuang caves — spent two to three years patching the broken pieces together with plaster. The restored panels, scholars point out, carried the fingerprints of their modern reconstruction as much as their ancient origins. At the Met, when the documentary team requested restoration records, very little was provided.
"The result became a huge mystery in Chinese art history," Chen notes.
The film introduces Wen Yucheng, the 87-year-old honorary director of the Longmen Grottoes Research Institute, who first began sorting the fragments in 1965 shortly after graduating from Peking University's archaeology department. He was on a three-person team investigating the looting.
Six decades later, he appears in Chen's documentary as a living bridge between the original crime and the ongoing effort to repair its damage.
Xiao Guangyi, a documentary studies teacher at Chengdu College of Arts and Sciences in Sichuan province, says she was deeply moved by Wen's lifelong devotion to the Longmen caves.
"Hearing an elderly scholar say that — how he missed the stones when he was away — is deeply moving. We see a tourist site. But generations of people have devoted their lives to protecting our civilization," Xiao says.
For Xiao, the documentary's most powerful moment comes when researchers test the fragment against the cave wall.
"Piece by piece, centimeter by centimeter — until it clicked. Suddenly you feel that all those efforts, all those generations of dedication, have finally found hope."
