Prequel, set before the maze, covering the solar flares and the release of the virus.
It is a different kind of book, closer to straight apocalyptic survival than the puzzle box of the trilogy. Some readers prefer it. I found it useful mainly as background rather than as a story standing on its own.
Reading it fourth, in publication order, is the right call. Taken any earlier it would strip the trilogy of its central mystery.
Read June 2024.
