Some people were asking why astronomy and celestial omens are so heavily featured and taken so seriously in this story and why ML is an astronomer. And when you learn the context behind it, it makes one appreciate the well designed plot even more.

Astronomy was heavily politicized in ancient China because of the Mandate of Heaven. The emperors relied on people's belief that legitimatacy of their power came straight from the Heavens. As long as the Son of Heaven has the Heavens' blessing all is right under the Heavens. When calamities and rebellions happened, people turned to the Heavens to interpret celestial omens to rationalize that the current dynasty is failing and its fall is morally justified. So those who seized power always tried to prove that they legitimately got the Mandate of Heaven by tacking on celestial events to their victory.

So since the early dynasties astronomers always had some sort of government body to closely watch the sky, to record celestial maps and to keep historical records, and were responsible for the lunar-solar calendar needed for planning of yearly religious events and agricultural works. The calendar in particular was of great importance, so when ML did that big job to update it to save FL, he was justified to ask for a big reward from the emperor in return.

Many astronomers were also prominent inventors, some of those inventions are shown in the drama - telescopes, hydraulic armillary sphere, water clock, earthquake detector.

So it's no wonder the emperor in the drama is very wary of celestial omens. Just like ML, the emperor may not really believe that they themselves can actually cause calamities, but they both know that people with ulterior motives can use them to undermine the government and emperor's rule. That's why it was explained in the drama why astronomers weren't allowed to interact with the court or meddle in wordly affairs - they could be influenced or bribed by corrupt officials who could be seeking to overthrow the government and stir up trouble. Their knowledge was for the emperor's ears only. That's why ML was so incredulous as to how wily FL, even with her power, managed to convince the emperor to have him join her in her investigations so she could regain her memory.

Astronomical events were prominently featured in the first case about the princess, in the fifth case about the crazy cult, in the final seventh case, as well as throughout all of the main plot. FL's father was set up by the villain, who used a bad celestial omen to further prove that her father was plotting to overthrow the emperor. So it was beautiful to see the villain getting poetic justice in the final seventh case, where a celestial omen was used against him to lure him into a hopeless situation with no way out.

And throughout all of the main plot ML often had something interesting to say pertaining the stars, be it a metaphor leading to a new way of thinking to figure out a clue, or something comforting or romantic to make FL feel better. I especially liked how he compared her friends to stars guiding each other to stop FL from hurting herself and believing that cursed lone star bs.

Their childhood connection story also began with a celestial omen and stargazing, which led to a whole chain of long term consequences and even influenced ML's career choice. The drama also has a nice song about these worldly entanglements, sung by Bai Lu herself.

Another thing, the final seventh case was called the Seven Misaligned Stars, which alludes to the Big Dipper constellation. It was viewed as the celestial mechanism of cosmic order, symbol of justice and Imperial authority, and was heavily scrutinized by astronomers to gauge how well the government fares. So constellation having something wrong with it means something troubling is gonna happen pertaining the government and the emperor.