The Apothecary Diaries 10 by Nekokurage
The further adventures of Mao Mao. Spoilers ahead for the earlier ones.
It opens in the middle of the cliff-hanger from volume 9, and indeed does not make much sense unless you remember the plotting to deal with the envoys.
Then onward. It deals with sickness of a maid, and Mao Mao's tendency to tunnel vision coming back to bite her, and it ends with a discussion of something from history and another cliff-hanger.