Kevin J. Anderson & Brian Herbert 
Dune: House Harkonnen #8 [PDF ebook] 

In reality not all Harkonnens are as cruel as they say, as Abulard makes an important decision that will send the Baron and Rabban into a vengeful pursuit. And as the tension rises in the thrilling prequel adaptation by authors Brian Herbert & Kevin J. Anderson, the Teilaxu commit unthinkable acts on Ix, Duncan takes a significant step in his training, and Liet faces an impossible and deadly choice on Arrakis!