Destiny: The Taken King has a item called Hadium Flakes and upon being reforged, they net the player one of three Legendary swords.
These items are found exclusively in chests on the Dreadnaught, and the video above from Arekkz Gaming highlights possible chest locations which have been discovered so far.
In order to complete the quest to gain a new sword, the player will need 25 Hadium Flakes in total. Note there is only one per chest.
The expansion was released today on PS3, PS4 Xbox 360 and Xbox One.
Be sure and check out our running Destiny: The Taken King guide which contains everything you need to know.