WARNING: The following article contains spoilers for Star Wars #50, by Kieron Gillen, Salvador Larocca, Guru-eFX, Clayton Cowles, Giuseppe Camuncoli, Cam Smith and Java Tartaglia, on sale now.
In the Star Wars franchise, 1977's A New Hope represents a major story of triumph for the Rebel Alliance as it took out the Galactic Empire's most powerful weapon, the Death Star. It proved to be a crushing blow to Emperor Palpatine and Darth Vader, who had clearly underestimated the Resistance brewing throughout the galaxy.
1980's The Empire Strikes Back, however, took a darker turn, one where the villains gained revenge. Not only did the rebels end up on the run, Vader won the film's core psychological battle. Unveiling himself as Luke Skywalker's father, he cut off the aspiring Jedi's hand and successfully goaded Lando Calrissian into handing over Han Solo.
Clearly, between both films, the Empire did its homework and rebounded, and the comics are now revealing just how this started. In Star Wars #50, we bear witness Vader using a rebel tactic by infiltrating the Alliance and planting seeds of betrayal via his own spy network.
This strategy paid dividends for the rebels in the Rogue One anthology movie, which gave Leia's soldiers the info needed to blow up the first Death Star. At his castle on the volcanic planet Mustafar, Vader is holding congress with his underlings in the wake of this, and he's realized they need to stop underestimating their enemies.
In fact, the first thing which comes to mind is to beat them at their own game, utilizing spies. It'd be an unsuspecting move because the Alliance views the Empire as an army who oppresses via brute strength. So Vader decides instead of a show of force, he wants to deploy this particular cerebral tactic, one his opposition wouldn't see coming.
He recognizes such a network would strengthen Palpatine's grip on the galaxy, giving the Empire eyes and ears across the cosmos. And so, we see just how far back Vader goes to achieve this purpose. The person he starts off this mission with is Queen Trios of Shu-Torun, a volcanic planet which has metal ores that are mined for war.
Just before the Empire took full control of Shu-Torun years earlier, Vader killed the entire royal family after they conspired to assassinate him, save Trios. She then became Queen, but was obviously forced to follow Palpatine's order. However, in the recent comics, she's been feeding the Rebellion information on the Empire, even leaking the details which saw the rebels try to liberate Mon Cala recently and fortify their own ranks. But as we see in Issue #50's backup story -- a flashback -- this was all a ruse.
Way before, Vader confronted Trios and began putting his master plan in place. He wanted her to leak the information to Leia and Co., so she'd gain their trust for a bigger play later down the line. The Sith Lord promises if she does this, he'd spare the lives of the people of Shu-Torun; a tactic he'd clearly deploy later on, strong-arming Lando and Cloud City in Empire.
Here, he intimidates Trios by pointing out a piece of the destroyed planet Alderaan (Leia's home-world which the Death Star destroyed in A New Hope) he sent her as a reminder of what Palpatine can do. Also, to end proceedings, Vader kills her entire military entourage, to ensure no possible record of this meeting would exist. In fact, Trios was so scared she even killed one of her bodyguards who mouthed off to the villain.
This is just the beginning as Vader wants to seed agents across the galaxy. The results are in his favor because after the Mon Cala battle, the rebels gather at the Mako-Ta base, with Trios joining Leia, Mon Mathma and Admiral Ackbar, to chart a way forward as they believe they've gained another win. Sadly, Trios has already informed Vader of things and she slips away just as the Empire's army appears, leaving the entire Rebellion scrambling for cover and facing the full brunt of Vader's wrath.