Horus Heresy Books - Betrayer and Mark Of Calth

News via Apocalypse 40K.

Betrayer by Aaron Dembski-Bowden - April 2013

The Shadow Crusade has begun. While the Ultramarines reel from Kor Phaeron’s surprise attack on Calth, Lorgar leads the rest of the Word Bearers deep into the realm of Ultramar. Their unlikely allies, Angron and the World Eaters, seem blind to the true goals of the mission, preferring instead to ravage each new civilisation they come across – but where Lorgar might once have chastised his wayward brother, now he seems only to encourage the frenzied bloodletting. Worlds will burn, Legions will clash and a primarch will fall... and the fate of the entire galaxy hangs in the balance.

Mark Of Calth - Edited By Laurie Goulding  August 2013
Anthology featuring stories from the Ultramar side of the war, for years after Calth. Confirmed are:
1) 'Calth That Was' (Graham McNeill) novella which links Remus Ventanus to the 40k Ultramarines continuity, along with Maloq Kartho before he becomes a daemon prince.
2) 'The Shards of Erebus' (Guy Haley) showing how Erebus learned to do his warp-travel thing, and where he got his athame dagger.
3) 'Unmarked' (Dan Abnett) following Oll Persson as he leaves Calth.
4) 'The Underworld War' (Aaron Dembski-Bowden) showing the expansion of the Gal Vorbak, and how they realise they've been left for dead by their Legion.
5) 'Athame' (John French) which is apparently a very "odd" story, following a particular knife. All we said was that it's not Erebus's knife.

Also confirmed are Rob Sanders, Anthony Reynolds and David Annandale.
 So that's another two books added to my shopping list for 2013. I'm guessing these are going to be in the new hardback formats, so add another three months or so onto the release dates for paperback versions (have we discussed my bookshelf ocd? Hardbacks are going to look weird suddenly appearing in the collection after 20 odd paperbacks).