The Tomb of Sargeras audio drama takes place before the mini-cinematic with Khadgar warning Varian and Anduin about the Burning Legion and before the ingame scenario where we as a player storm the Tomb with Varian and company. It tells the story of Gul’dan (from the Draenor timeline) reaching the Tomb of Sargeras on the Broken Shore with the help of Kil’jaeden, intending to find a way for the Legion to reach Azeroth. Meanwhile Khadgar is doing his best to find Gul’dan to prevent said invasion. I found the interaction between Khadgar and Gul’dan to be quite interesting. I never really was a fan of Gul’dan, but seeing his side of the story did make him evolve from the boring 2D villain to something more.