Letting you know I exist, and letting you continue to exist, are both dangerous to me

What a wonderful sequel to The Three Body Problem. A coherent, plausible, and utterly desperate future imagined through the lens of totally assured destruction of our species.

Probably the best ending to a second-in-a-trilogy that I've ever read. The reader is Luo Ji's Wallbreaker and it's perfect (that's not a spoiler - if you're interested in sci-fi, this trilogy is essential, in my opinion).