Orbiting Lothal, an Imperial light cruiser, with Agent Kallus and Lieutenant Lyste on board, was at battle stations because a shuttle had been reported stolen from the Lothal Spaceport and they were moving in to intercept before it could escape. The pursuing TIE Fighters disabled the shuttle and the cruiser caught it in a tractor beam. After docking the shuttle, Kallus attended the boarding party. Two Stormtroopers had the thief in custody, who turned out to be Ezra Bridger, along with his two droids Chopper and AP-5. Kallus had Ezra taken to the brig, and as soon as they were alone Ezra brought up his reason for being captured. The Rebels tought the Empire was onto Kallus, and he had come to rescue him before they capture and execute him for treason. Just then Lieutenant Lyste showed up to inform Kallus that Grand Admiral Thrawn's fleet had arrived and had summoned the both of them aboard his ship. Lyste also brought along Ezra so he could show the Grand Admiral how effective he wes when dealing with a Rebel threat. Accompanied by Chopper and AP-5, Kallus, Lyste and Ezra arrived on Thrawn's Star Destroyer by shuttle, and after sending Ezra to the brig the two Imperial officers made their way to the Grand Admiral's office. Meanwhile, Chopper and AP-5 reported back to Kanan Jarrus and Rex of their current situation. Hearing that they were aboard Thrawn's Star Destroyer, their plan to rescue them had become more complicated. They could not use their clearance codes to get aboard because they were for light cruisers. So Chopper and AP-5 needed to get the ones for Thrawn's Star Destroyer, but that was easier said than done since they could not just download them from a basic terminal. They needed to find an officer's port.
Kallus and Lyste arrived at Thrawn's office, where they found Thrawn practicing his combat skills. As they entered the office, they were greeted by Admiral Konstantine and Colonel Wullf Yularen of the Imperial Security Bureau. Kallus knew Colonel Yularen, as he was one of his star pupils at the academy. Just then, Thrawn arrived, who explained Yularen's reasons for coming to Lothal. He briefed Kallus and Lyste about the possibility of a Rebel spy in their midst, and with Yularen's assistance they intended to uncover his identity, much to Kallus' worries. He also noted that few are among suspicion, including Kallus and Lyste. So they would eventually be questioned. Thrawn found it essential that they find their spy, since he was on the verge of locating the Rebel's secret base, leaving Kallus even more concerned. With the interview over, Kallus and Lyste were dismissed from Thrawn's office. They bump into Governor Pryce, who congratulated Lyste on his success in apprehending the thief of the stolen shuttle, much to his delight. As the two officers walked away, Kallus warned Lyste to be cautious with the Governor. He convinced him to suspect that Govenor Pryce was the Rebel spy, and as he did so he switched his code cylinder with his own. Lyste fell for it, and set out to keep an eye on her. Meanwhile Governor Pryce visited Thrawn and Yularen in the office. It turned out the interviews were part of a plan Thrawn had set up in hopes of exposing the identity of their Rebel spy. Giving away the fact that he was close to finding the Rebel base, he hoped the spy would take the bait and warn the Rebels. Colonel Yularen also had a lead. He had just received word that a coded Rebel message was beamed from their ship right after Ezra was transferred to the detention block.
Down in the detention block, Kallus showed up at Ezra's cell, where he found AP-5 and Chopper arguing over what to do first: free Ezra or get the clearance codes. Kallus deactivated the security systems and entered Ezra's cell. He told him about Thrawn's progress in locating the Rebel's base, and they needed to remove it from his data base before he pinned it down. With Ezra disguised as Lieutenant Lyste, The four of them sneaked back into Thrawn's office. They gained access to the clearance codes for Thrawn's ship, and transmitted them to Kanan and Rex. Then they erased Atollon from Thrawn's data base and switched it with another planet. However, they received word from AP-5 that Thrawn was coming back. Ezra and Chopper hid behind one of the pieces of art on display while Kallus hid in Thrawn's private gym. Noticing the Sentry Droids, Kallus reprogramed them to attack Thrawn as a distraction, allowing Ezra, Chopper and himself to escape. However, Thrawn caught the site of Ezra fleeing, mistaking him for Lyste. After taking out his two Sentry Droids, he alerted Colonel Yularen.
Meanwhile, Kanan and Rex arrived at Lothal, and using the codes they had received boarded Thrawn's ship disguised as Stormtroopers. However, the Imperials were onto them, and Govenor Pryce showed up to arrest them. When Kanan tried to use a Jedi mind trick on her, She had him shot him with a stung blast, and then tackled Rex, all while Lieutenant Lyste was watching nearby. Seeing her fight off a trooper, and not knowing that a Rebel was in that armor, made him assume that Pryce was the traitor. Pryce quickly overpowered Rex in physical combat, and just before she could shoot him she was hit by a stung blast from Lyste. Ezra, Chopper and AP-5 boarded the shuttle, but Kallus chose to stay behind. He knocked out Lyste and switched back his code cylinder. Then as the Rebels fled, Colonel Yularen and Imperial forces arrived in time to see Kallus accuse Lyste of being the Rebel spy.
Later, Kallus, Pryce, Konstantine and Yularen were all gathered with Thrawn in his office, discussing the proof they had against Lyste. They all congratulated Kallus for capturing him, and everyone was dismissed. However, Colonel Yularen remained for a private conversation with Thrawn. It turned out they did not actually believe that Lyste was the Rebel spy known as "Fulcrum", and Thrawn confirmed that Kallus was, much to the Colonel's shock. He found it hard to believe that one of his own students were capable of betrayal. However, Thrawn did not intend on arresting him just yet, as he believed that agent "Fulcrum" may prove useful in the Empire's fight against the Rebellion.
- Taylor Gray as Ezra Bridger
- Freddie Prinze, Jr. as Kanan Jarrus
- Dee Bradley Baker as Kassius Konstantine / Captain Rex
- David Oyelowo as Alexsandr Kallus
- Stephen Stanton as AP-5 / Pilot / Thrawn Trooper #2
- Tom Kane as Wullf Yularen / Stormtrooper #3
- Liam O'Brien as Deck Officer / Imperial Tech / Yogar Lyste
- Mary McGlynn as Arihnda Pryce
- Lars Mikkelsen as Thrawn
- David Acord as Stormtrooper #1 / Stormtrooper #2
- Dave Filoni as Thrawn Trooper #1
- Wullf Yularen, voiced by Tom Kane, returns in this episode, having appeared previously in Star Wars: The Clone Wars.
- This is the third episode that Hera Syndulla and Garazeb Orrelios haven't appeared in and the second episode that Sabine Wren hasn't appeared in.
- Originally, the whole episode was going to be filmed through the eyes of Kallus, but the idea was scrapped and only done for the first scene after deciding it would be too tricky on their schedule.
- This is the first episode where Ezra is disguised as Lieutenant Lyste.
- There are several Easter Eggs in Thrawn's office, three of which were identified in the subsequent Rebels Recon episode: The Holy Grail from Indiana Jones, Commander Gree's helmet from Revenge of the Sith, and Ralph McQuarrie's art of Lothal.