The Crossing at Zhiyao

In a modern library, Lin Shiyao's fingers brushed the tattered cover of an ancient book. The next moment, the ceiling lights became dim candle flames, and air tinged with mildew and bitter medicine rushed into her nose.

“Miss, it's time for your medicine.” An impatient old matron came in carrying a bowl of murky black liquid. A line of glowing text appeared over her: Keep her weak. Make sure nothing goes wrong before the wedding.

Lin Shiyao lowered her eyes and accepted the bowl. The library bookshelves in her mind rose with a rumble, and a book titled An Inquiry into Ancient Poisons opened by itself. Her fingers trembled slightly as she calmly said, “Thank you, Matron. I dreamed of my birth mother last night, and my heart is heavy with grief. Might I take this medicine with candied fruit, as a small keepsake of her?”

The matron froze. In the eyes of the usually meek Third Miss, she saw a calm, steady light she had never seen before...

(Period mystery + strong heroine) (Look forward to the story between the male and female leads, too!)