A Republic and Jedi task force comes to the aid of the planet Empress Teta, which has managed to hold off the Krath, but the Sith cult drives the Republic out of the system at the First Battle of Empress Teta. Ulic Qel-Droma is infected by Aleema Keto's Sith magic during an attack on the Republic's command ship Reliance I, and he unknowingly begins to slip towards the dark side.
The Jedi Conclave on Deneba is disrupted by Krath war droids, and the servant droids at the conclave attack the Jedi at the event. The Jedi destroy their attackers, but Arca Jeth is killed by Krath dorids in the battle.
Ulic Qel-Droma attempts to infiltrate the Krath from within, but is seduced to the dark side by Aleema Keto. Qel-Droma kills Satal and becomes the Krath's leader alongside Aleema, and a Jedi rescue mission fails when Qel-Droma refuses to depart.
Around the same time, The power-hungry Jedi Exar Kun searches for Sith teachings and discovers the spirit of Freedon Nadd on Onderon's moon Dxun, where he is trained in the ways of the dark side before heading to Yavin IV to acquire more power. Kun ultimately kills Nadd's spirit and seeks out Ulic Qel-Droma to eliminate a potential rival.
Nomi Sunrider organizes a second rescue mission at the same time that Kun arrives on Empress Teta, and Kun and Qel-Droma clash in a duel. However, the duel is ended by the spirit of Marka Ragnos, who anoints Kun and Qel-Droma as Dark Lords of the Sith as well as Master and apprentice. Joining forces with Kun, Qel-Droma refuses Sunrider's attempt a rescue, and the two Sith form the Brotherhood of the Sith.
↑The New Essential Chronology states that the Ruusan Reformation occurred in 1000 BBY, which is the zero point of the calendar based on the Ruusan Reformation, so the difference between the calendar based on the Battle of Yavin and the Ruusan Reformation's year-notation system is 1,000 years. This date is derived using simple math based upon other confirmed dates.