It’s been an 20 years since Valve released Half-Life 2, one of the most influential first-person shooters in the history of gaming. To mark the anniversary, the developer and publisher has made a two-hour documentary that assembles most of the team that worked on the game – and reveals that there could have been a Half-Life 2: Episode 3.

The Half-Life 2 Anniversary Documentary shares plenty of secrets from the development of the game and its episodes, including the revelation that the company was saved by a Korean intern in its legal battle against Vivendi. Towards the end of the documentary, we’re shown concept art for a cancelled third episode. And while we’re currently hyped about the Half-Life 2 RTC remake, the revelations about Episode 3 are bittersweet.