These are all hard sci-fi, and much like Dark Mirror, given today's troubles, it's simultaneously entertaining while being intellectually stimulating, but in a way that feels relevant, even if not immediately actionable.
The first is what got me hooked, and back into reading.
The Wages of Humanity, is a short story by Liu Cixin. The short story used to be available by itself on Amazon, but now it's been disappeared[1]. It can be found as the last story in The Wandering Earth: Classic Science Fiction Collection.[2]
An assassin is being offered exorbitant sum to kill the three poorest people for some reason, and the book explores why, to a thrilling conclusion.
Since I found it as a stand alone story I cannot comment on the rest of the books in that collection. From there I read into The Three Body Problem[3], and Dark Forest by Liu Cixin; first two books of the Remembrance of Earth's Past trilogy. The only reason I don't mention I have not (yet) finished reading the third book.
[1] This link now returns a 404: https://amazon.com/dp/B00CSW0UZI but it's what the URL my Kindle points to. Search does not find the stand alone edition.
[2] https://amazon.com/dp/B00CXUKNA2
[3] https://amazon.com/dp/B00IQO403K