The Dark Below
From Destinypedia, the Destiny wiki
The Dark Below is the first DLC for Destiny, released on December 9, 2014. The Dark Below takes place in the Cosmodrome and within the Hellmouth, and involves stopping the Hive god Crota from being resurrected and invading Earth. Players are guided by Eris Morn, a new Tower vendor with a grudge against Crota.