Faster Than the Speed of Light

Faster Than the Speed of Light is a dungeon & raids achievement earned for completing the Vault of Lights within 5 minutes of enter in the Halls of Origination on Heroic difficulty.

Strategy
The event is completed when the door releasing opens. If you fail the achievement the first time, you have to soft-reset the instance so that Brann spawns again and you can start the event anew.