The Emperor is furious. Magnus the Red, primarch of the Thousand Sons Legion, has made a terrible mistake that has endangered the security of Terra itself. Having no other choice, the Emperor orders Leman Russ, primarch of the Space Wolves, to take his brother into custody on Prospero — the home world of the Thousand Sons. Capturing the planet of sorcerers is no easy task, but Russ and his Space Wolves will not back down. Burning with wrath, Russ intends to deliver Magnus into the hands of justice and raze Prospero to the ground.