Vortex. Troy Denning (Star Wars Fate of the Jedi 6)

In Book Six of the bestselling nine-book "Star Wars Fate" of the "Jedi" series, the suspense crescendoes as the Skywalkers and their treacherous Sith allies race against time to discover the origins of the mysterious Force-entity known as Abeloth. When they begin to uncover secrets better kept hidden from mortal minds, no one is surprised to see the uneasy partnership erupt into violence. But they are surprised at where the investigation leads: to the home of the reclusive Fallanassi, who may hold in their hands the future of the Jedi Order itself.