On today's heroic daily (Regicide), if you go to the area where you find the exotic sword knight quest behind the door in the Founts, you will find the Taken light and will have to chase it. There will be Taken further in instead of Hive where you kill the knight with your sword. I'm still trying to figure out what to do after chasing the light and killing Taken so if anybody wants to join in the discovery let me know.