The Left Hand of Destiny novels 2

Chancellor Martok's triumphant return to the Klingon homeworld is met by treachery and upheaval. As the demons of the general's past rise up, so too does a usurper to the Imperial Throne, one who knows exactly how to crush Martok and all who stand with him -- and who won't be satisfied until they are ashes under the foundation of a new Klingon Empire.

Martok fights for the right to lead the Klingon Empire. With the secret of his usurper exposed, the ousted chancellor and his ragtag band of followers embark on a desperate plan to retake the empire. But while Worf, Ezri Dax, and the crew of the IKS Rotarran go in search of the Klingons' most revered icon of power, Martok is dealt the most crushing blow of all.