Mercy of the Dragon (The Horus Heresy Primarchs)

A Horus Heresy story
The primarch Vulkan of the Salamanders has ever been focused on defending the people of his adopted home world, Nocturne. Not even the coming of the Emperor could easily sway him from this task…READ IT BECAUSE
It's an exceptional insight into Vulkan, and into his deep ties to Nocturne, and a look at the relationship between this most human of the primarchs and his father, the Emperor.THE STORY
As the Emperor of Mankind comes to Nocturne in the guise of the Outlander, He tells Vulkan of his destiny in the stars as one of His Primarchs. It is Vulkan's destiny to lead a Space Marine Legion into the stars and conquer the galaxy in his father's name. But the Lord of Drakes, ever caring for the folk around him, is hesitant to leave his world unprotected and so the Emperor must convince him of the worthiness of His Crusade.

This story is also available in the Sons of the Emperor anthology.