The Galactic Empire has done some pretty heinous things over the years – most notably destroying entire planets – but the atrocities committed in Andor season 2 episode 8 are among the worst in the Star Wars franchise’s history.

In this instalment of the Disney+ show, the Empire’s two-year propaganda war against the peaceful people of Ghorman turns violent, as Imperial forces open fire upon innocent protesters in the capital city of Palmo. As well as unleashing legions of Stormtroopers and rookie soldiers on the populus, commanding officers authorise the use of KX enforcer droids.

The unfortunate Ghor have little chance against these custom-built killing machines, and they mercilessly tear through the citizens as if they weren’t there. Indeed, it’s the first time we’ve really seen what they’re capable of on screen, though Andor season 2 episode 8 doesn’t mark their first appearance of these robot killers in Star Wars…

Spoilers ahead! Proceed with caution if you’re yet to watch Andor season 2 episodes 7, 8 and 9

What is a KX Enforcer Droid?

Not to be confused with the Trade Federation/Separatist battle droids that made for remarkably easy cannon fodder during the Star Wars prequel trilogy, Imperial KX Enforcer droids are a rather more serious proposition. They’re strong and fast, never get tired, and shoot much more accurately than the famously target-shy Stormtroopers. They’re also capable of piloting spacecraft and communicating directly with computers, and – unlike most droids in Star Wars – have nothing in their programming to prevent them harming sentient lifeforms.

According to expanded Star Wars lore, the Empire dodged the fact that the Senate had banned military droids in the wake of the Clone Wars by referring to them as security droids.

Where have we seen KX Enforcer Droids before Andor season 2 episode 8?

Their screen appearances include a brief cameo in The Book of Boba Fett episode “The Return of the Mandalorian”. In a flashback scene, KX Enforcer Droids can be seen marching through Mandalore on the so-called Night of a Thousand Tears, during which the Empire massacred the planet as part of its “Great Purge”. This event takes place a few years before the events of Andor in the Star Wars timeline.

A pair of KX units also crop up in Andor season 1 episode “Announcement”. One is used to apprehend Cassian Andor (Diego Luna) at a beachfront development on Niamos, while another can be seen beating up alleged troublemakers on the beach.

The most famous KX, however, is K-2SO, one of the heroes of 2016 film Rogue One: A Star Wars Story.

How does an Imperial KX Enforcer Droid become a hero of the Rebellion?

The droid who will later become known as K-2SO is one of the Enforcers unleashed to crush the Ghorman rebellion. As Cassian and Rebel associate Wilmon Paak (Muhannad Bhaier) try to make it out of Palmo safely, the droid gets them in its sights, repelling blaster fire and flinging citizens around like they were ragdolls. They’re saved at the last minute when Samm (Abraham Wapler), a member of the Ghorman resistance, drives an Imperial transport into the droid, smashing it in two.

When Cassian eventually escapes the planet at the end of Andor season 2 episode 8, he takes the battered back to the Rebel base on Yavin IV.

At the conclusion of the following episode – after Cassian has rescued Mon Mothma from Coruscant – we see Rebel Alliance technicians reactivating the droid after swapping out its cortex and applying some “impulse suppression” measures. Everybody present is, unsurprisingly, on high alert for the big switch-on, but any concerns prove short-lived as the droid talks with the familiar tones of K-2SO (provided by Alan Tudyk who reprises his voice and performance-capture role from Rogue One in the Andor season 2 cast).

The character provides a crucial bridge between the Andor season 2 story and Rogue One, in which K-2SO plays a key role in the brave team of Rebels who recover the Death Star plans from Scarif. He’ll also become Cassian’s best friend and is – as far as we’re aware – the most sarcastic droid in the entire Star Wars galaxy. We’re guessing that isn’t exactly what the Empire had in mind when they designed him…

The final three episodes of Andor season 2 stream on Disney+ from Wednesday 14 May.