The peak of the Horus Heresy. The Emperor VS Horus, with sanguinius dead at Horus’s feet and space marines watching everything unfold. However, everything stops when everyone feels a disturbance in the warp. Something not from the world they currently reside or maybe even universe. A rift opens on the ceiling and a person falls and hits the ground with incredible force. Everyone stares at this person, not knowing what or who it is that could have interrupted such a pivotal moment. Savior?