King of the Mountaintop is a new Story mission in Destiny Rise of Iron.
Walkthrough
Step One
The mission opens with your ship coming in low over a snow-covered forest and dropping your Guardian to the surface. Your in-mission instructions come directly from Lord Saladin, who leaves his post at the Iron Banner to take charge of your mission personally. The Fallen House of Devils have been on a campaign of raiding Golden Age research facilities and have taken an intense and very unwelcome interest in the abandoned Vostok Observatory that sits high atop Felwinter Peak, which is also the location of the Iron Temple. Reinforcements are on their way to repel the Fallen, but they will take some time to arrive. Your mission is to battle your way to the top of Felwinter Peak and to keep the Fallen at bay long enough to save the mountain from falling before the primary Guardian force arrives.