Crucible

At the heart of a rift in space and time awaits a monster from the darkest imaginings of man, a daemonic being of immense power and evil. A lone Grey Knight, Brother Istafel, is sent on a desperate and suicidal mission to banish this dark entity. But as he approaches the Crucible rift, he realises that all is not as it seems... Why was he sent on this mission? What is the purpose? And do his masters expect him to survive?

Read it because
It shows the total focus and amazing self-sacrifice of your average Grey Knight, along with the dark truth behind the names that the sons of Titan carry with them.