Liu Cixin's
The Dark Forest, the 2nd entry in his famous
Three-Body Problem trilogy, is 99p today at
Amazon UK (and £4.99 at
Kobo UK, but should be eligible for their
Price Match Guarantee).
In this specific case I believe the marketing blurb on the page reveals too much, so I won't be reproducing it here, however if you already read (and enjoyed)
The Three Body Problem, this sequel is a must-read.