We’ve been repeatedly griping here that Rebels has been mostly rote this season, with artificial tension that always results in a happy, predictable victory for our characters. “An Inside Man” isn’t quite a game changer in that regard, but it’s definitely an episode which is much darker in tone and ratchets up the threat level. This week, it definitely feels like there’s some real risk to these characters. None of the main cast members die, but there’s a few points where it felt like a genuine loss could have been coming.

“An Inside Man” takes us back to Ezra’s homeworld Lothal, where the local rebellion under Ryder Azadi (Clancy Brown) has infiltrated an Imperial factory developing a new, classified fighter. They’re engaging in some colorful sabotage which causes Imperial speeders and walkers to take themselves out in the right conditions. Ezra, Kanan, and Chopper join Ryder’s inside man, Morad Sumar (Liam O’Brien), to join the efforts to mess around with Imperial equipment.

Big mistake. While the typically incompetent Imperials are fumbling about trying to find saboteurs, a surprise inspection by Grand Admiral Thrawn (Lars Mikkelsen) means that shit is about to get real. Thrawn opens the inspection by ordering Sumar to test the last speeder he personally inspected, and caught in the trap, Sumar is killed by his own explosive. Realizing Thrawn means business, the Rebels attempt to get out, but not before they can figure out what this factory is building. Unfortunately, this is precisely when Thrawn decides to put the factory on lockdown, because he’s planned ahead knowing that the Rebels would be there.

The episode is equally divided between Kanan and Ezra’s attempt to escape and Thrawn’s careful study. The latter is more important–Thrawn spends a lot of this episode doing nothing, and yet doing everything. Repeated scenes in his office show that Thrawn’s penchant for art collection includes samples of culture related to the Rebels themselves. He’s very carefully studying our cast, and he’s learned that they always come back to Lothal. Hence, for every move Kanan and Ezra make, Thrawn is a few steps ahead of them, realizing that they’re changing disguises or headed towards certain exits even without laying eyes on them. Thrawn comes off as bone-chillingly intelligent, and the slow build we’ve gotten towards these moments all season is finally paying off.

Two big reveals come on the heroes’ side of things. One, Kanan and Ezra escape only by a fortunate encounter with the new Fulcrum–who, as many predicted, turns out to be Agent Kallus. Thanks to his debt to Zeb last season, Kallus has become a Rebel sympathizer and is willing to act the part of a secret aide–even if it means Ezra gets to beat the crap out of him to make it look convincing. The help is appreciated, but we have to wonder if this spells doom for Kallus long-term. At the episode’s end, Thrawn lets on to Kallus and Pryce that he knows a traitor is among them, and they’re going to sniff them out and make them as useful as possible. We’re in a very dangerous cat-and-mouse game at that point: does Thrawn know that Kallus is the traitor? And does Kallus know that he knows? This is going to be fun.

The other goodie is that it turns out Thrawn’s new fighter is, in fact, the TIE-Defender, a brand of TIE with shielding. The classic version of the TIE has no shields and is a crappy ship that relies on numbers over protection in order to be effective. The TIE-D lacks that problem and will be a deadly new threat for the Rebels. For fans of the old Expanded Universe, this was a definite “SQUEE” moment–the TIE-D originated in the Lucasarts TIE Fighter computer game in 1994, where Thrawn also made an appearance. With Rebels and Rogue One expanding the Imperial arsenal, dipping into the EU well and pulling out the TIE-D is a great moment.

Lastly, it’s worth noting that this episode was gorgeous. We’ve complained before that this season has been a bit lazy, constantly being set in space or on empty rock worlds. A return to Lothal means we get a highly detailed cityscape and even more detail in the Imperial factory. The battles with speeder bikes and AT-ATs fighting a rogue AT-DP were as much fun as they were visual eye candy. Good job, Rebels production crew.

Rating: Five TIE-Ds out of five.