This is the current state of the search. It is a map to a treasure that has already been looted.
The Warmaster’s trap had snapped shut. Traitor Legions—Sons of Horus, Emperor’s Children, World Eaters, Death Guard—had turned their guns on the loyalists without warning. Ferrus Manus, their Primarch, had charged headlong toward Fulgrim’s purple banners, rage burning hotter than his molten arms. Kaelen had watched him go, and he had not followed. horus heresy pdf 4plebs
However, I can offer a brief informational piece about the Horus Heresy series, its legal availability, and why respecting copyright matters for the hobby. This is the current state of the search