Leia didn't go directly back to Alderaan from Ralltiir. Instead, she had the Tantive IV divert to the planet Kattada's main spaceport of Haloeda, so she could meet with the ruler of Kattada, Madam Mia Ikova, a rebel sympathizer. She may not have been able to get the supplies to Ralltiir herself, but she wasn't ready to give up yet, and she requested Mia's assistance in getting the items to the rebels on Ralltiir. The rebel they'd rescued, Basso, was still healing in the bacta tank, so she hadn't been able to speak to him yet about the information he claimed to have.
She was preparing to depart Kattada when a report arrived than an Imperial patrol ship was landing. Antilles, of course, wanted to get Leia out of there immediately, as did Mia, but she refused to leave Mia and her people alone to face the Empire. So she remained at Mia's side while the Imperial ship landed. Antilles wanted to start a firefight immediately, but Leia forbade that as well, instructing him not to fire any weapon without her order.
"Leia, my people are only lightly armed," Mia said nervously. "We're a peaceful socieity. We can't hope to fight Imperials."
"I know, Mia," Leia said. Alderaan was much the same, after all. "But it won't go that far. I'm sure we can talk our way out of confrontation." She was confident she could manage it just like she had on Ralltiir.
A squadron of stormtroopers and Imperial officers emerged from the ship. "Nobody move!" the commander ordered. "You're all under arrest in the name of his Excellency, Emperor Palpatine. That includes you, Princess Leia Organa."
"On what charge?" Leia demanded. "On whose authority? I was given leave to travel freely by Lord Tion."
"Lord Tion, yes," Commander Karg said. "But you see, Lord Tion's jurisdiction does not extend beyond the Ralltiir system. His 'permission' was overruled by Lord Vader's order. Lord Vader gave orders that if you were discovered any place other than Alderaan, that you and your ship were to be seized and searched."
"This is outrageous!" Leia snapped. "Even Lord Vader doesn't have the authority to arrest a member of the Senate without just cause. Especially when my visit here is...."
"Purely a recreational one," Mia finished for her, putting a hand on Leia's shoulder. "Kattada is famous for its beaches. The Princess was merely enjoying--."
"Enjoying what?" Karg scoffed. "Your spaceport? We're a long way from the beach, Lady. But since you're so anxious to vouch for the Princess, maybe we should place you under arrest as well!" He grabbed hold of Mia's arm and yanked her away from Leia.
"What? Unhand me!" Mia cried.
Her guards came rushing up to help her. "Take your hands off Madam Ikova at once!" one ordered.
Karg signaled his troops with his free hand. The stormtroopers didn't hesitate to open fire on Mia's guards.
"Don't shoot!" Leia yelled. "Stop shooting!"
"Leia," Mia said faintly, clutching a hand to her side. She'd been struck by a stray bolt and now collapsed into Leia's arms.
Leia caught hold of her and gently lowered Mia to the ground. "You shot her!" she accused the commander. "She's dying! There was no need. I would have come peacefully. You didn't have to kill her."
"What is one life, more or less, to the Empire?" Karg said, standing over her. "Besides, now your cooperation is assured."
Leia looked up defiantly. She lifted her comlink to her mouth and gave one command: "Fire!"
Antilles opened fire with the gun turrets of the Tantive IV. Leia was low enough to the ground that the energy bolts passed over her head, but they struck the stormtroopers. In the resulting chaos, she grabbed hold of Mia and started to try to drag her away.
"You think this will save you, Princess?" Karg said, stalking after her, ignoring the fighting around them.
"You're the ones who started the violence," Leia said, holding Mia protectively.
"This display of resistance only delays the inevitable," Karg sneered, pointing his blaster at her head. "And seals your fate. And I'll end it. Let's see how willing your crew is to fight when your life is in danger. Or better yet, let's see how quickly their foolishness ends when you are no longer alive to protect. Prepare to die, Leia Organa."
But Antilles hadn't let Leia out of his sight, and a well-aimed blast from the weapons of the Tantive IV struck Karg. He crumpled to the ground, writhing in agony. "Your Highness!" Antilles said, darting out of the ship to her side. "Are you all right?"
Leia looked from Mia to Karg, who lay groaning in pain on the ground. "Get them to the ship. Both of them," she ordered. "What about the crew? Is anyone hurt?"
"No causalties to report," Antilles said. "But if the Imperials send a message to their fleet command...." He took Leia's comlink and sent an order to the Tantive IV. "Target the Imperial ship's landing gear and communciations array!"
Once the Imperial ship was crippled, Antilles near-dragged Leia away from the fighting and on to the safety of the Tantive IV. While Mia and Karg received medical attention, the Tantive IV lifted off to move clear of the battle. Moments later, a request from Mia's retainers to board was received, and Leia went to meet them in the medical center.
Basso was still in the bacta tank, healing from his injuries. Mia was conscious but weak, and greeted her father as he rushed in. "I'm dying, father," she said calmly. "Please, no tears. The future will be what it will, and the past cannot be changed. I don't welcome death, but I accept it. Maybe my passion will have some meaning. Maybe it will start something that is long overdue."
"Mia, I'm so sorry," Leia said, tears in her eyes. "If I had never come to Kattada...."
"Hush, Princess," Mia said, giving her a faint smile. "Remember why you came here. You sought to help the freedom fighters on Ralltiir. They still need your aid. You can't let what has happened sway you from your original purpose." She looked up to her father and weakly clasped his hand. "Father, I pledged Princess Leia our help. It is my dying wish that it be granted." Her father nodded, clinging to her hand as she drew in a last breath, then lay still.
"No, help me!" came the demand from Karg's bed. One side of his face was horribly burned from his wounds, and after seeing Mia die so bravely, Leia could only watch him impassively as he struggled to sit up. "I won't die like this!" he said. "I demand that you take that man out of the bacta tank and place me in it!"
"The bacta wouldn't do you any good," the doctor tending him said. "I'm afraid your wounds are too extensive."
"No! This can't be happening to me!" Karg said. His eyes went to Leia. "This is all your fault! When word of this gets back to my father...you'll pay!" His words ended in a fit of coughing. He reached for Leia, but his arm fell back to his side, and moments later he was dead.
"I'm sorry you had to witness that, Your Highness," Antilles said. "But he was right. When word of this gets out, you will be named an enemy to the Empire, like your father. Then even your royal status won't be able to shield you. Their communications are cut, but their shields are operative. The only way to get at them is with a ground assault. The Imperial know all they have to do is wait. Eventually, another patrol will be dispatched to find them."
"Meaning we need to stop them first," Leia murmured. But the people of Kattada weren't fighters, and neither were her crew. She had some knowledge of battles from her classes in Fandom, but they really needed someone with a lot more experience. She turned to the bacta tank and studied Basso. Fortunately, they had someone right here.
[NFB due to distance. From the Star Wars Empire comics #5 & #6 "Princess...Warrior, Part 1" and "Princess...Warrior, Part 2."]