It seems the episodic version of SiN has been abandoned after just one instalment following a recent shake up at developer Ritual.
SiN Episodes was the first episodic FPS delivered via Valve's Steam software. The first, and now, only, episode debuted in May 2006.
Earlier this month, the Dallas-based studio appointed Ken Harward as its new studio director after former boss Steve Nix left for id - just one of a number of staff departures that saw the team behind SiN Episodes, disappear; project lead Shawn Ketcherside had left the company after nearly six years in September and QA lead Michael Russell also confirmed via his blog he had left the company.
Comments that the game is now abanonded have come from the Games For Windows podcast, wherein one editor comments: "I've personally been trying to contact the head there, Tom Mustaine, and haven't been able to get too much information. What it seems to imply, obviously, is that Sin Episode 1 didn't do well."