The Painter Imprisoned in the Mural

I am a restorer of Dunhuang murals. When I was restoring Cave 465 of the Mogao Grottoes, a few lines of words suddenly appeared behind the peeling murals under the ultraviolet lamp: >"Save us! In 848 AD, we are trapped here forever." >After checking the information, we found that the signer Tashi Rangbo was a painter during the Tibetan rule in Dunhuang. >As the restoration progressed, blood letters asking for help with the same handwriting appeared in different corners. >When the instrument detected that the composition of the text was human blood mixed with mineral pigments, the eyes of the statue of the Master of the Corpse Forest in the mural reflected the chains shaking behind me.