Warhammer 40,000 (WH40K) is a science fantasy universe with a heavy emphasis on the fantasy. Heroic Space Marines (think knights in power armor) battle against every threat, alien, human, and demonic, that the galaxy can throw at them. It is a dystopian setting in every sense of the word. The Imperium claims to rule all humanity in the name of an immortal but very much physically-dead emperor. Progress of any kind has halted, and people live lives of drudgery, superstition, and fear.

There is also an epic backstory. Some ten thousand years before the “present” of the WH40K era, or about 30,000 AD, there was massive insurrection by nine legions of Space Marines that cast their lot with the foul gods of Chaos. This has become known as the Horus Heresy, after the previously honorable and beloved Warmaster who first raised the banner of rebellion in the name of Chaos. The bright and glorious future promised by the then-living Emperor of Mankind came to a halt in a civil war of fire, iron, and blood.

One of these Traitor legions, the fanatical Word Bearers, attacked the noble and loyal Ultramarines as they mustered unsuspectingly at the world of Calth. Though the Ultramarines blunted the Word Bearer attack, Calth was left in ruins. The survivors of the battle sought shelter from triggered solar storms, along with their enemies, deep underground. The story of the invasion of Calth is told in the excellent novel by Dan Abnett, Know No Fear.

This began the so-called Underworld War, and the unabridged audiobook anthology Mark of Calth refers to the clock that the Ultramarines left running ever since the surprise attack against them. The Ultramarines know how to hold a grudge. The clock still ticks, some ten thousand years later. It also refers to the way that the radiation burns of their poisoned sun has marked the loyalist warriors still fighting for their survival on wrecked Calth.

Mark of Calth features short stories by Black Library’s best writers, and in a brilliant move, each has also been released as an audiobook of about one hour or  more in length. The readers employ their rich tones and voice changes well, and the effect is fantastic. This is such a winning combination that I can’t help but implore other SF and fantasy publishing houses to do the same with their own shorter works. It would certainly help breathe some life into the often-overlooked but vibrant world of SF/F short fiction, which deserves to be better known outside of a handful of yearly anthologies.

Publisher Black Library has an advantage, in that the success of the WH40K miniatures game, as well as several videogames, has created an eager market for such stories. This is military fiction with a strong dose of fantasy and Lovecraftian horror, and the stories in Mark of Calth deliver action and chills in equal measure.

The Traveller, by David Annandale and read by Jonathan Keeble, is a morbid, Cthulhuesque tale of a loyal subject of the Emperor of Mankind who kills heretics wherever he finds them. But has he gone too far in his pogrom against those he deems traitors? And what is the actual source of the voices that he hears?

The Shards of Erebus, by Guy Haley and read by Jonathan Keeble, follows one of the most sinister of all figures in the WH40K universe, the Dark Apostle Erebus of the Word Bearers, and the ultimate instigator of the treason that would swallow the previously loyal Horus and nine entire legions of marines. He is ever-plotting, and The Shards of Erebus follows him as he grasps for ever more power and knowledge of Chaos.

Dark Heart, by Anthony Reynolds and read by David Timson, stars Reynolds’ infamous Word Bearer Dark Apostle Marduk, who is a menace to humanity in the current timeline of WH40K. In the Horus Heresy, he is a scheming would-be apprentice of the Dark Gods. He slays his own teacher of the dark art, but can he somehow survive the retribution of both his own high command and the vengeful Ultramarines too?

Athame, by John French and read by David Timson, tells the story of a blade of Chaos, an athame, created to take life, as it winds its way through human history. In a smart turn, the story of the blade is being told to the blade itself.

So far, Mark of Calth has been extremely good, and I look forward to the remaining stories.  I would recommend it on the basis of just the stories mentioned above.  Several remain on my to-do list, however.  My consideration of Mark of Calth will continue in Part Two of this review.

Marc DeSantis