Natasha set the Quinjet on autopilot, the quiet hum of the engine filling the brief pause in the tense atmosphere. She unbuckled her seatbelt in a swift motion, then turned in her seat to face the projector screens in the main bay area. Her fingers moved deftly over the console, typing with calculated fury. Within seconds, the room was bathed in a soft glow as a cascade of data, photos, and documents unfolded before them, the secrets of the mission splashed across the walls.

"Here's what I know," Natasha began, her voice steady but cut with cold professionalism. "Helmut Zemo—the guy who set you off at HQ—worked for the Sokovian army. His wife, son, and father died during the attack last year. So, vendetta's likely." She paused, tapping a few keys to pull up a set of images. A grainy photograph materialized on the screen, showing a chaotic scene from Berlin. "She, however," Natasha continued, enlarging the photo, "was a different story."

The image was blurry, taken during the heat of battle, but the woman's face was unmistakable. Bucky's eyes narrowed instinctively as he studied her features. Natasha tapped again, and the name flashed across the screen accompanied by a driver's license photo: Lorea Soltero.

"Initially, I couldn't find much on her," Natasha admitted. "Nothing connects her to us in the last fifteen years, but here's where it gets interesting. Her late husband? He used to work with Dr. Truett Hudson."

The moment the name escaped Natasha's lips, Steve's gaze shot to Bucky, his concern immediately registering. Bucky's body tensed, muscles stiffening like a coiled spring, and a brief flicker of something dark passed through his eyes. Natasha seemed to notice the shift, but she pressed on.

"Hudson worked with the U.S. government in the Weapon X Program. Publicly, the research was working towards a cure for cancer, but actually..." She paused, her lips curling into a grim smirk.

"They were trying to recreate the supersoldier serum." Bucky's voice cut in sharply, his tone low and gravelly. "They didn't just stop there. They rifled through alien technology too. Medically. They brought out the big guns. They—" He swallowed hard, but the words spilled out, and he couldn't stop the flood.

Natasha's eyes softened for a brief moment. But her focus remained, and she continued, tapping at the screen again. "Yes, but he was found..." Her fingers hesitated on the keys, the next piece of the puzzle just out of reach. "Murdered in his lab, along with an associate."

Bucky's expression hardened, the muscles of his jaw twitching as he clenched his teeth. "No one was ever prosecuted," Natasha added quietly. "The internal cause of death pointed to foul play, but no one ever named a suspect. No current or archived files ever pointed to a culprit."

Bucky's breath caught in his throat, and his voice dropped to a whisper as he spoke, barely audible but filled with grim resolve. "I killed him. The Winter Soldier killed him." He looked up briefly, his gaze distant, as if he were seeing a different time. "He was getting too close to a viable serum... so they sent me to kill him. I couldn't leave a witness."

Steve's voice cut through the confession before Bucky could descend further into the memory. "How do you know all of this?" Steve asked, trying to keep his voice calm, but there was a crack of disbelief in it. The enormity of the revelation was starting to sink in.

At the exact same moment Bucky murmured, "How did you find out all this?"

Natasha met both their eyes, her expression hardening for just a second before she answered, her lips curving into a rare, knowing smile. "Nothing's a secret from me forever," she quipped, though the confidence in her voice was quickly tempered.

Her gaze shifted downward. She paused before continuing, her voice quieter now. "Tony doesn't know any of this. I wasn't sure how much to clue him in on. Jen—"

Her words faltered for a moment as something flickered across her face. A quiet, almost inaudible gasp escaped her lips, and she quickly covered it with the back of her hand, trying to push it down. A fleeting moment of vulnerability, but it wasn't lost on Steve. He had been with Natasha long enough to read her like a book, and in that instant, he could see the pain she was struggling to hide.

Just as quickly, Natasha was comforted by a warm, familiar hand on her shoulder. Steve's eyes locked with hers, his expression softening. She looked up at him, her gaze steadying, and she exhaled slowly, a shaky breath escaping her. "Look, the two who..." Natasha hesitated, clearly weighing her next words, "caused the scene in the CIA. We don't know why, but they... took her. They kidnapped Jenny."

Bucky's face contorted in rage, his fists clenching as he stood up, his voice filled with an overwhelming urgency. "The name... What was the name of the associate?" He took a step forward, his body tight with restrained fury.

Natasha's eyes flicked between Steve and Bucky, and for the briefest of moments, she hesitated. Then, with a sharp exhale, she gave them the truth.

"Soltero. Jovanni Soltero."