This mod is based on the old Half-Life 2 storyline, but instead of using the original HL2-wc-maps sources, it's authors are creating all of the maps from scratch, and thus are not limiting themselves in their creativity.
There are currently eight chapters completed, starting with Gordon's arrival in City 17 and ending at the junkyard where Eli's den is located.
This release contains all the maps of the first part with minor fixes.

Installation:
Put the "darkinterval-part2" folder from the archive into your "sourcemods" folder. Then turn on the "upcoming-" function in the "Betas" option of your Source SDK Base 2013 Singleplayer in the Steam tools list and restart.

Discussion thread
Dark Interval on ModDB