Happy 20th to Quake @idsoftware! As a gift to the fans, we created a new episode of the game https://t.co/BTgju8tLuI pic.twitter.com/gHlxBgjcBU — machinegames (@machinegames) June 24, 2016

MachineGames is serving up the special episode for free via zipped RAR file that you'll need to extract into a new folder named "dopa" into Quake's main directory. To run the episode, you'll need to start up a new single-player game and launch the executable "dopa" file in the same folder and tear it up from there!

If you've never played Quake before, now's a great time to get into it, especially as it's part of the Steam Summer Sale and can be nabbed for as little as $2.50. You'll have the benefit of a whole other episode to play.