Know No Fear is a book written by Dan Abnett. It is part 19 of the marathon The Horus Heresy novel series. The novelist, Dan Abnett has several books in this series, where each one is better than the other. The subject novel and the series is a contemporary science fiction novel. The narration of this 11 hours long book is done by Gareth Armstrong.
Being totally unaware about the wider Heresy and following in the footsteps of the Warmaster Horus excessively mysterious orders, Roboute Guilliman had no choice but to return to Ultramar in order to congress his Legion for war against all the orks, who are massing in the strong Veridian system.
Without giving any prior warning or ultimatum, their expected allies in the Word Bearers Legion setup a shocking invasion of Calth, while going on to scatter the Ultramarines fleet and eventually slaughtering everyone, who comes in their path. This in one way or the other confirms the worst ever possible scenario that Guilliman could ever imagine.
All that Lorgar means is to adjust their bitter rivalry with their opponents, once and for all. Just by the time, when the traitors call for the foul daemonic hosts, the Ultramarines were forced into a deadly and grim struggle.
Dan Abnett not just in The Horus Heresy, but otherwise as well has done some amazing work in literary writing. It is because of his skills and immense creativity that he managed to make a reasonable fan following for himself in quick time. A good couple of novels from Dan Abnett that you could think about listening to are First and Only and Horus Rising.