There isn't a 3rd volume yet, they're up to chapter 16 in the main series with a lot of side stories.
Lots of people were sharing rips of the series here, and so any threads about ITW started getting deleted immediately. I think most of the discussion left.
Here's an archive of one of the last 4Chan threads about it.
https://boards.fireden.net/y/thread/2195824/Search for the secret and ye shall receive.
