Isard's Revenge (1999) is the eighth novel in the Star Wars: X-wing series. It marks a return by writer Michael A. Stackpole to the series he created, after a hiatus of three novels by Aaron Allston. In returning to the series, Stackpole brought back a number of elements that made the original four books popular: General Wedge Antilles has returned as commander of the New Republic X-wing unit Rogue Squadron, and former Imperial leader Ysanne Isard is once again the villain.
After the death of Grand Admiral Thrawn in Timothy Zahn's The Last Command, the New Republic has decided to go after the numerous warlords terrorizing the galaxy. Its first target is Admiral Krennel. The mission seems straightforward at first, but then Isard appears from the dead, offering her services and using New Republic prisoners as bait (the same prisoners with whom Corran Horn spent some time aboard the Lusankya). After several initial victories against Krennel, the New Republic begins taking savage political blows from Krennel thanks to Isard. Meanwhile, Iella Wesseri and Mirax Terrik begin investigating a series of strange events and clues, and discover that somebody is setting up a trap for Rogue Squadron.
Unfortunately, they are too late to warn Rogue Squadron. While on a mission, the Rogues are ambushed by an entire wing (6 squadrons, or 72 fighters) of assorted TIE-Fighters. With the unexpected aid of a squadron of TIE Defenders, the Rogues manage to win, but not before losing Janson, Asyr, and their two replacement pilots. It is revealed that they were rescued by Isard, and that the Isard working for Krennel is in fact a clone. She makes a deal with Wedge, saying that in return for helping the Rogues defeat Krennel and retrieve the Lusankya prisoners, she is to be granted amnesty for all past crimes. Wedge has no choice but to agree.
While most of the galaxy, including Krennel, believe that Rogue Squadron is dead, Mirax finds out that they are still alive when Whistler and Gate escape Isard's base. The New Republic then receives a message from Wedge outlining the final decisive attack on Krennel. During the battle, Isard betrays Rogue Squadron and denies their commando and fighter support. Corran decides to land his Defender and liberate the prisoners himself, taking Ooryl and Nrin Vakil with him. Fortunately, Admiral Ackbar suspected a trap and brought secret reinforcements, including a large commando force. Krennel and the Isard clone are killed in the battle, and the Lusankya prisoners are liberated.
Meanwhile, Isard takes her extra forces and attempts to steal the Lusankya, which was captured by the New Republic during the Bacta War and almost fully repaired. However, Iella and Mirax predicted her actions and thwarted Isard's plan. Isard was killed in the process.
At a party celebrating the success of the campaign against Krennel, Janson, who survived Isard's ambush, is reunited with Rogue Squadron. Asyr, who also survived, keeps news of her survival secret, wanting to return to Bothawui and try to change the Bothan way of life for the better.