Abyss is novel by Troy Denning released on August 18, 2009. It is the third novel in the Fate of the Jedi series and published as a hardcover.
Story
Galactic Alliance Chief of StateNatasi Daala continues her P.R. war with the Jedi Order as two more Jedi Knights, Yaqeel Saav'etu and Bazel "Barv" Warv, fall under the mysterious Force psychosis. In addition to having Tahiri Veila put on trial for her murder of Imperial Grand Admiral Gilad Pellaeon two years earlier during the Second Galactic Civil War, Daala puts more and more heat on the Jedi for them to give up the insane Jedi they have. So the Solos and some of their own mentally-stable Jedi allies manage to take the delusional Knights that they have over to the Jedi base on Shedu Maad. Beforehand, however, medical healer and Jedi Master Cilghal had managed to narrow down the cause of the Force psychosis: each of the Jedi Knights had been children who were under protection of the Jedi's base in The Maw during the Yuuzhan Vong War. Therefore, whatever the cause of the psychosis was had originated within The Maw. Meanwhile, within the Maw Cluster, Luke and Ben Skywalker arrive on a mysterious space station called Sinkhole Station, where they meet the Mind Walkers, who were mistaken by the Aing-Tii in the previous novel to be Mind Drinkers. The Mind Walkers are a collection of Force-users who try to leave their physical forms in order to join the Force. The Skywalkers ask the Mind Walkers what Jacen was doing with them, and the Walkers reveal that Jacen left them because he sensed a dangerous presence in the Force. Ben even confirms such a presence which he vaguely remembered as a toddler during his years in the Maw amidst the Yuuzhan Vong War; he shielded himself off from that presence as well as shielding himself from the deaths and horrors of the Vong's invasion of the galaxy. As a result, Luke decides to perform Mind Walking in order to not only contact Jacen from the great beyond, but also to find out what that threat Jacen had sensed was. Ben joins him in this task. Meanwhile, the Sith squadron of the Eternal Crusader, one of its members being Vestara Khai, find the Sith Meditation Sphere known as Ship on a mysterious world populated by carnivorous plants. The survivors of the Sith squad are rescued from these plants by a mysterious being named Abeloth. However, Vestara comes to find out that Abeloth is not all that she seems, even after she helps the Sith get Ship back. Then, with Abeloth staying behind on her planet, the Sith proceed to complete their previous mission of killing Luke Skywalker. Back in Sinkhole Station, Luke and Ben Mind Walk to the place that the Mind Walkers call "beyond shadows". There, the Skywalkers meet the late-Anakin Solo, as well as their dead wife and mother, Mara. But in the end, their meeting with Jacen is the most important, even as it is the most tense. Jacen tells the Skywalkers that his motivation for wanting to unify the galaxy during the Second Galactic Civil War was to prepare it for a great threat that he sensed on Sinkhole Station. With that information they got from Jacen, the Skywalkers return to real life, but are soon ambushed by the Sith squad. However, as individual members of the squad turn on each other, it becomes easy for Luke and Ben to kill nearly every one of them in combat. The only survivor of the group is Vestara Khai, who Luke uses a Dathomiri blood mark on so that she could lead the Skywalkers back to the Sith's homeworld.
