- Blackstone AKA Noctilith AKA Pariah Stone is mined from smooth, dark, obsidian or onyx -like rock. Worlds which feature blackstone (amongst other 'supernaturally valuable resource[s]') are known as Quarry Worlds. Note that the blackstone on such worlds needn't be in 'raw' form - worked blackstone in the form of obelisks/pylons/tomb complexes etc. counts. Indeed it is not clear from Forgebane whether raw blackstone is even a thing - rather it reads as though Cawl's efforts are focussed upon cannibalising existing structures.

- Cawl recognises that blackstone repels the warp. Forgebane presents this as a great new discovery; which is obviously untrue since the Cadian pylons have long been recognised by in-universe sources as holding back the Eye (plus there are artefacts such as null rods in the service of Imperial institutions, which match the description of blackstone).

- Cawl sends out agents to recover and/or protect blackstone wherever they can find it. The first of these is Magos Dominus Dentrex Ologostion (the Magos in the Forgebane campaign).

- The Necrons are also looking for blackstone (quite why they need to if their tomb complexes are made of it isn't clear. Possibly they're trying to reclaim structures which they're misplaced since sixty million years ago?)

- The Technomandrite Crypteks (hey, remember them from the 5th ed. Codex?) understood how to manipulate blackstone in order to make it repel the warp. (It isn't clear if other Crypteks understand the process as well. Presumably the various lord-level 'Architects of the Great Work' would understand the basics at least). After the Silent King defeated the Technomandrites and Magistrakh at the outbreak of the Triarch's war against the Old Ones, the survivors apparently went off and joined other Dynasties. Presumably this explains why the Forgebane Cryptek - Agdahax the Technomandrite - is part of Sautekh forces. Post-biotransference the Crypteks were apparently 'exiled' and locked in stasis by 'anti-Chaos protocols put in place against an empiric breach of cosmic scale'. (It certainly was good of the other Dynasties to take in members of the conclave which they had agreed with the Triarch to attack in the first place, harbour them until biotransference, give them powerful Cryptek bodies, and then have the foresight to seal them up just in case something like the Cicatrix Maledictum should happen...)
The Technomandrites are only now beginning to come out of stasis.

- The Technomandrites lack the numbers and influence to build a galactic blackstone network. The Adeptus Mechanicus have the resources but not the knowledge of how to harness the blackstone. If the Necrons and Mechanicus were to work together, they could possibly achieve the goal.

- Magos Dominus Dentrex Ologostion goes to Amontep II in the Ultima Segmentum (at the southern-most tip of Sautekh's territory). There seems to be some confusion in the narrative as to exactly what Ologostion's role actually is. Page 3 and the fact that the Skitarii are Martian imply that he has been dispatched from Mars, or is at least Martian himself, but page 18 implies that he is 'The Magos Dominus of Amontep II's Vrackian Megacomplex' - ie. presumably from the Amontepian priesthood.

- Ologostion and his Skitarii Rangers travel to an area called the Vrackian Ridge which is a large shallow, dusty, caldera. They detect the presence of blackstone, and Ologostion calls in his drop-lander, Bellerophobos, to use it's thrusters to clear away sand from the area. A group of obelisks and dolmen henges are revealed. They are then ambushed by Immortals and Wraiths. The Skitarii win scenario 1 and defend the Magos.

- One of the dolmens forms a gateway, out of which emerges Agdahax and his Lychguard. The Skitarii are surrounded, but then the Armigers arrive and rescue them. The Skitarii win scenario 2.
It is not clear if the 'dolmen gates' mentioned are actual dolmen gates (ie. entrances to the webway) or gates which happen to be in the form of dolmen stones (which some dolmen gates are, and some aren't) (ie. hyperspace portals). If they are proper webway- dolmen gates, why are there a bunch of them just out in the open on the surface of the tombworld? Given their significance to the Necrons, shouldn't they be defending them better? At least by putting them indoors?

- The ground shakes and sinkholes open up. Towers and ziggurats rise from the sand, and the Vrackian Ridge is revealed to be a vast Necron fortress. One of the Armigers chops the top off a 'towering obelisk' with it's chain-cleaver (can't have been all that towering then...). The detached capstone is sufficiently small that Ologostion can pick it up and tuck it under his robes. The Mechanicus forces run away and escape aboard Bellerophobos, the Necrons apparently powerless to stop them for some reason. The Skitarii win scenario 3 and recover the blackstone fragment.

- Ologostion is apparently going to send the lump of blackstone to Cawl (who's half the galaxy away, so that might take a while). However apparently the loss of the top of just this one [short] blackstone obelisk 'would bear a terrible cost - with its noctiliths compromised, Amontep II had been left vulnerable indeed'. Its then implied that a warp breach occurs.
But what about all the other blackstone? They lose one little chunk and the whole lot stops working? Why bother with huge pylon networks if just one little chunk is what's doing the work? The Cadian pylon network was badly damaged, and while slowly failing, was still functional, but removing this little lump causes Amontep II's defences to fail immediately?
It all gets a bit too silly at the end.

The background of the box art for Forgebane bears no relation to the description of the area of the battle(s) described in the narrative.

The Martian raid by five Shroud class cruisers is referenced directly (although not really in relation to any other events, which is a bit odd - are we supposed to assume that the Necron ships were in search of blackstone on Mars?) which proves that that wasn't retconned by the 5th edition Codex: Necrons either (which should hardly be a surprise by now, but it's nice to be proven right so often!)