Meet Stern-Duty, Inquisitor of the Ordo Hereticus.
She's good at what she does, very good in fact. She's banished Daemons, shut down the threat of insurrection and even dealt with the odd cult of the Chaos Gods.
However, when an investigation goes wrong, Stern-Duty has to confront her own daemons. However as she is picking up the pieces, Inquisitor Stern-Duty starts running into something big.
Something big enough to threaten all life in Equestria.

All things hang in the balance, and the decisions of one young woman can change the fate of millions.

(A warhammer 40k and MLP crossover)