This is a gem of a detective romance historical. I've watched a couple of this genre (Miss Truth, Maiden Holmes--both I liked very much too) but this is the first one that is of this length (55 episodes) which allowed for expansion of subplots and supporting characters' growths. When watching this show, you'll want to pay attention. Skipping through will take you out of the mystery and investment in characters. This drama is kind of like if our main characters (and supporting characters) went on side quests (in this case, on cases) and all of it relates back to the main plot of fighting the antagonists. The majority of the show is the characters on that journey and away from the capital where the ministers and emperor live.

There are some focus on the political plot and several names--that I personally never quite connected to who is who--but I like that it's not a big mess about ministers fighting and scheming against one another. It's mostly one main clan/villain group from the ministers VS our main characters. When the story show scenes about those ministers, emperor, and talking, it doesn't take too long. The main focus is the characters figuring out mysteries in the cases and trying to get evidence to fight the antagonist.

Allen and Seven's acting and chemistry as Lu Yi and Yuan Jinxia is a perfect combo. Allen plays a perfect cold stoic imperial guard who gradually shows his feelings. Seven's Jinxia is lovable with perfect comedic timing and also perfect tearful and sorrowful expressions. Her tears make me want to cry too. And she can fight! Like actually fight and hold her ground. A lot of times, the FL is written to be clever but not able to physically fight, which is frustrating as then she becomes a bit of a burden and in need of saving. Jinxia generally fights her way through things and it's only through the real tough situations that she needs saving from. (In fact, she saves the male lead a couple times! Love it.)

This is your classic dislike-to-love couple and their slow burn romance is well done. Truly, I think this is one of the slowest burn romances I've seen in a Chinese drama. They're not going to fall in love within the 5th or 10th or even 15th episode lol but all the set-up of trust and believing in each other's capability is there and it's SO good. It's well written and organic.

The supporting characters too had my hearts. One great thing is that the actors really look like characters from this time and era. I don't know how quite to explain it. For some dramas and some actors, they look like they're actors wearing costumes rather than genuine characters in this time setting. I love that the characters in this show all look like genuine characters.
I adore Shangguan's development and her romantic arc with Yang Yue and their romance is also well done.
Xie Xiao is a hilarious character, at times a bit annoying, but endearing.
Lin Ling and Uncle Begger! I adore them too.
Han Dong as Yan Shi Fan, the antagonist/villain, is great; he has such a beautiful face, but he's so evil. I love to hate him because he's such a terrible person with such a beautiful face. Well done, Han Dong! I hate your character so much.

I only have two criticism:
1) the panning into their eyes or fists is not a good directing move. Maybe to general viewers, it's not as abrupt, but I never got used to those cut close-ups. Yes, Allen and Seven's expressive eyes are great, but I would like to see their whole face rather than just their eyes. It's too awkward to see just their eyes personally.
2) Sometimes, the political subplots or the antagonist don't feel connected to the main story with the main characters. It's not as strongly connected. I'll be watching our main characters and then we'll have a cut away to something happening back in the capital and I'm like "oh right, there are some schemes happening here. Forgot about that." Ultimately, our main characters come back to the capital and these schemes become stronger, but I think since our main characters are away for quite a while doing their investigations, the stuff happening at court is put in the back of mind. Also, I think because of this issue that as the series reach about mid-way point, the plot does feel a tiny bit dragging. Because the main characters are off on their own plots, the subplots feel irrelevant and dragging even though it'll become important later.

Overall, a delightful and interesting show with a strong cast and acting. The 55 episodes is a little bit intimidating to get through, so watch this when you're in the mood to pay attention and for detective historicals with slow burn romance.