A digital-only Horus Heresy short story by John French, Ordo Sinister is the first Black Library story to feature this particular Titan Legion, who have only recently been explored by Forge World in their book Inferno. Taking place during the Webway War, it sees a single Titan holding back an entire daemonic incursion on its own, for this is no ordinary Titan. Commanded by Prefect Hydragyrum, controlled and powered by…unconventional means, Borealis Thoon is a Psi-Titan.
Titans are cool. Psychic Titans though? This is a new level of cool, and French tackles the idea head on by showing us the practical (and disturbing) workings of the Titan as well as the strange existence of the sort of person capable of piloting it. The story is told in two interlinked parts: a present tense depiction of the battle in the webway and a past tense exploration of how Hyrdragyrum came to be there, and ties in thematically with recent stories like The Master of Mankind. French keeps a narrow focus, telling a good story and touching upon some interesting concepts without worrying about explaining everything away; it’s not a detailed look at the Ordo Sinister overall, but rather a teaser of how interesting they’re going to be.