I made a vague mention in my fanfic of Andromeda attending Bella's trial, and then I wrote this, which I rather ran out of inspiration on and never finished, but might play with someday...
She didn't want to be recognized, she didn't want to speak to anyone. She slipped into the dark, forbidding stone chamber, with its rows and rows of benches and stood near the back, against the stone wall and in the shadows. It was cold, the stones of the chamber didn’t offer any heat, and she pulled her cloak tighter, feeling as though she couldn’t be there. Though really, she has as much right as anyone to see how this would play out. More, really...
The accused was her sister. If Andromeda did not know Bellatrix had awaited trial in Azkaban, she never would have guessed it. Rodolphus and Rabastan looked nervous, young Barty Crouch looked terrified, but Bella surveyed the court that would judge her as though they merely bored her. She was chained to the chair, they all were, but there was no concession to that in the way she sat, back straight, a haughty tilt to her chin. Forever an aristocrat, Bella, even facing a life sentence in Azkaban.
And she deserved it, Andromeda reminded herself fiercely. Deserved that and worse. For torture. For murder. For the thoughtless destruction of so many lives. The hatred in the room was palpable, shown in the face of everyone watching, in their stony silence. Did she feel nothing? No regret? Andromeda studied Bella’s face, which was familiar and yet entirely strange. Crouch’s voice rang out through the chamber, startling her.
“You have been brought here before the Council of Magical Law, so that we may pass judgement on you, for a crime so heinous that we have rarely heard the like of it within this court,” Crouch’s voice rose as he spoke, to drown out his son’s cries. Andromeda could feel for the boy, for he was only a boy, not even eighteen. Bella could be so persuasive, so charming when she wanted to be, Andromeda had no doubt she had recruited the boy, she had pushed him to do what he had done, if he had done anything at all. Bellatrix would never trouble herself to help someone falsely accused.
“We have heard the evidence against you. The four of you stand accused of capturing an Auror-Frank Longbottom-and subjecting him to the Cruciatus Curse, believing him to have knowledge of the present whereabouts of your exiled master, He-Who-Must-Not-Be-Named.”
The Cruciatus curse. Bella had mastered it long before it was covered in sixth-year Defense Against the Dark Arts. They barely mentioned the Unforgiveable curses at Hogwarts, only mentioning what they were in the hopes their students would never need to fight them. That had been a great joke in the Slytherin common room.
“You are further accused,” Crouch was shouting now, over the pleas of the boy, and the dry, choking sobs of his wife, “of using the Cruciatus Curse on Frank Longbottom’s wife, when he would not give you information. You planned to restore He-Who-Must-Not-Be-Named to power, and to resume the lives of violence you presumably led while he was strong.”
Lives of violence. What had she done? What horrible acts had she committed in the years since Andromeda had left. She had always been a wild, impulsive child, but when had she sunk into such darkness? Where did such hatred come from? What had Voldemort done to her?
“I now ask the jury to raise their hands to raise their hands if they believe, as I do, that these crimes deserve a life sentence in Azkaban!”