From Destinypedia, the Destiny wiki
Hull breach: The players will spawn at the Dreadnought Hull breach, as is common, the cabal and Hive are fighting. The players can ignore this and proceed down a corridor ,entering the Mausoleum.
Mausoleum: After entering the players must go to the rupture and fight off Hive and Taken enemies such as Knights, Wizards, Thrall,and Acolytes After killing the enemies, the players must enter the rupture teleporting them to The Founts.
The Founts: After spawning, the Players will proceed through a long corridor and the arrive at The Asylum.
The Asylum: Immediately after going through a hallway, there will be a ball of white,taken energy. When the player approaches the ball, it teleport in between the pair of steps,and getting closer triggers a fighting sequence. The players must kill Taken enemies to proceed. At the back of the room there will be a door that the players must approach and wait for it to open leading to a hallway and another rupture.
Mini boss: Ta'aun,Hand of Oryx will step out of the rupture,and will begin firing at the players. Taken will spawn, joining the fight. When Ta'aun is at around 60% health, Baxx,Hand of Oryx will appear from the rupture and begin firing eye blasts at players. The two act the same as any colossus or ogre. After they are killed the rupture will open,the players must step into the rupture to be taken to the Trench way.
Trench way: Across from the players, there will be an entrance to Oryx's throne room, which will be populated by Wizards, Knights, and Acolytes who will recede into the darkness of the hall way behind them. Oryx will also taunt the players welcoming them,and creating a bridge across to proceed. By going either left or right the players will arrive at a long hallway illuminated by the aforementioned white ball of taken energy. The ball of energy will move to the far side of the room,leaving a trail of White, ethereal fire. Upon reaching the end of the hall the taken energy will illuminate Oryx's sigil and after a moment or so,the light will turn a dark red-orange opening the door,and the players will finally arrive at The Alter of Oryx.
Alter of Oryx: The room will be near pitch -black ,aside from red undertones. The shadows will recede into the center revealing Oryx's silhouette. Oryx will then full appear and his sword ,Willbreaker, will materialize and he will grasp it starting the final fight of the mission. Taken will spawn and Oryx's debuff , "Grasp of the king " will drain the players super energy. Oryx will teleport multiple times during the fight stating his contempt for the player. When he is at around 20% health he will teleport the players to a pocket dimension of sorts where he will shoot void blast,spawn Taken thrall, and will charge at the players with his sword in hand,keep in mind that this is the only time he can be damaged in this phase. After defeating Oryx, there will be a cutscene and a credit roll scene.