The Case of the Hosta Leading the Palace

I found a letter in Concubine Xian's clothes. It was a lotus-colored t-shirt with a tear under the armpit, and the stewardess gave it to me to sew. On the fourth stitch, my fingertips touched a hard object - a very small folded secret letter. There was only one line in the letter: The third day of the twelfth lunar month, Ci'en Temple, no time. I should have stuffed it back. But I opened it.