Pathways into Darkness happened in 1993.
Pathways into Darkness was created in 1993-08.
Veil of Darkness happened in 1993.
Shining in the Darkness happened in 1991.
Master of Darkness happened in 1992.
Throne of Darkness happened in 2001.
Operation Darkness happened in 360.
Pools of Darkness happened in 9801.
Jewels of Darkness happened in 1986.
The Darkness II happened in 2012.
Realms of Darkness happened in 1986.
It has to do with "toward the heart of darkness", "in the heart of darkness," and "out of the heart of darkness." It seems nicely organized to me, but where these breaks specifically happen- I'm not sure if its where the book breaks or just within the story. ...If that makes sense. :)
Most anabolic pathways are divergent, while catabolic pathways are convergent.