The Empire has captured a shuttle blasting its way out of Lothal. The pilot: Ezra Bridger. Kallus orders him brought to the detention cells. Also on the ship, however, are two droids who claim to have been aboard the shuttle when it was stolen...

After Ezra informs Kallus that he's there to extricate him, the ISB Agent is called to Thrawn's ship. There, he meets Colonel Yularen, his old mentor. Yularen will oversee the investigation to root out the rebel spy. Meanwhile, Kanan and Rex, in stormtrooper armor, make their way to Thrawn's craft.

Thrawn is on the verge of locating the rebel base, and is determined to catch the traitor soon.

Kallus, Chopper and AP-5 in tow, visits Ezra in his cell. He needs the location of the rebel base so he can remove it from Thrawn's list. They leave for Thrawn's office, where Chopper can alter the Imperial's records.

Kallus secures an Imperial uniform for Ezra, who uses a Jedi mind trick on the stormtrooper guarding Thrawn's office, and they use Lyste's security device to gain entrance. Chopper sends docking codes to Kanan, and then erases the rebel base location from Thrawn's map, adding another planet in its place.

But Thrawn has arrived. The rebels hide, while Kallus absconds and unleashes Thrawn's assassin droids upon the Grand Admiral.

While his override codes do not work, Thrawn eventually destroys the machines.

Kanan and Rex come out of hyperspace and are cleared to land, but Yularen is suspicious. Governor Pryce greets Rex and Kanan to place them under arrest. Kanan is hit with a stun blast, while Rex battles Pryce. Lyste, convinced by Kallus that Pryce is the traitor, stuns her from behind.

This gives the rebels the chance they need to escape. Kallus, however, elects to stay behind. By blasting Pryce, Lyste will seem to be the rebel spy. With the hunt for Fulcrum over, Kallus will be able to do more good for the rebellion from within the Empire.

Kallus us commended. In private, however, Thrawn and Yularen have misgivings. Indeed, the Grand Admiral is convinced that Kallus is the spy. And Fulcrum may prove more valuable to the Empire than Kallus ever was.