A Thousand Sons

"All is dust..."

- Book's tag-line

A Thousand Sons is the twelfth book in the Horus Heresy series

Plot Summary
A Thousand Sons is the story of Magnus the Red and the Thousand Sons Legion of Space Marines, and for the most part takes place before the Heresy beginst. Following a reprimand by the Emperor of Mankind for dabbling in sorcery, Magnus and his Legion secretly continue to study sorcery despite being forbidden to do so.

Magnus learns through sorcery of his brother Horus' impending betrayal, and tries, again through sorcery, to warn the Emperor hoping the news would justify his disobedience. However, Magnus overreaches with his powers and causes damage to a vital and secret project the Emperor was undertaking, endangering the safety of Terra itself in the process.

The Emperor is enraged and orders Leman Russ and his Space Wolves Legion, accompanied by other Imperial forces, to bring Magnus and his Legion to Terra to account for themselves.