The Ghost Halls (Angels of Death, #20)

In the silent ruins of a devastated eldar craftworld, most unusual figures stand vigil… Brother-Captain Pelenas awaits the arrival of the mysterious aliens to reclaim what is theirs. But why are he and his Grey Knights Purifiers waiting for the eldar? And will they be able to achieve their mission without bloodshed?

Read it because
It's a lovely little quiet tale of the Grey Knights when the battle is done, packed with tension and with a surprising twist that will change the way you look at a Grey Knights character forever...