Not only that, but they've managed to breach the wall surrounding the Cosmodrome in Old Russia, and it's up to the player to drive them back. They've managed to get their claws on some Golden Age technology called SIVA, a self-replicating nano-virus that they're using to enhance themselves and weapons to gain an advantage in their never-ending war against humanity. The Fallen are back, and this time they're more dangerous than ever.
Its story is centered on the player's ascension to a next generation of Iron Lord, a multi-mission adventure that largely takes place in a brand new Earth zone dubbed the Plaguelands.
Destiny's fourth expansion is a more modest affair than The Taken King in terms of its size and scope.