On the planet Cato Neimoidia, Jedi generals Obi-Wan Kenobi and Anakin Skywalker lead clone troopers to capture Nute Gunray, Trade Federation viceroy and one of the leaders of the Separatists.

Gunray narrowly escapes to rendezvous with General Grievous and the rest of the Separatist Council, but he leaves behind his walking chair equipped with a specially-constructed holotransceiver.

While Kenobi and Skywalker pursue the constructor of the chair, General Grievous is commanded by Sidious through his apprentice Count Dooku to relocate the Separatist Council to Belderone, where a Republic fleet lies in wait for them.

Kenobi and Skywalker seek out the artist, a Xi Charrian, who tells them to find the designer, contracted by Sidious, to build the holotransceiver built into the mechno-chair.

Palpatine's increased calls for public surveillance and restriction on freedom of movement and action prompt Senators Padmé Amidala, Bail Organa, and Mon Mothma to persuade him to pull back from the brink.

In the bowels of the planet, trace elements lead Jedi Mace Windu, Shaak Ti and Republic intelligence to track down the same Darth Sidious that Count Dooku had been meeting with, the tower described by the Twi'lek pilot.

[6] The starting point for Labyrinth of Evil was a line of dialogue from Revenge of the Sith in which Obi-Wan Kenobi briefly mentions to Anakin Skywalker "that business on Cato Neimoidia", an event from their past which is not further elaborated upon in the film.

[3] Labyrinth of Evil was originally planned to include the death of Asajj Ventress, an antagonist from other Star Wars works whose story arc had remained unresolved by that point, but it was ultimately excluded from the final novel.

[6] Luceno prepared a list of questions for Star Wars creator George Lucas to help inform the writing of Labyrinth of Evil.

[6] Labyrinth of Evil was one of the first Star Wars works to feature General Grievous, who would serve as one of the primary antagonists in the Revenge of the Sith film.

Among the changes were a more drawn-out sequence of Coruscant being attacked by droid starfighters, and a newly added story featuring Obi-Wan Kenobi and Anakin Skywalker on the planet Nelvaan, something only briefly mentioned in the final chapters of Labyrinth of Evil.

"[9] In Library Journal, Jackie Cassada felt that "[s]pot-on characterizations of familiar series characters and a genuine feel for the space opera genre" made it a strong addition to the Star Wars book line-up.

He said the novel's portrayal of General Grievous in particular "underscores Luceno's ability to make strange beings and habitats seem lifelike", and that the book "achieved a standard that should satisfy even the most faithful fans".

[1] Caleb Bailey of Comic Book Resources included a scene from Labyrinth of Evil in which Obi-Wan Kenobi becomes drunk on a list of the funniest moments from the Star Wars Expanded Universe.