Set immediately after episode 5.19, Judgment Day Part 2
Gibbs gave her the news. He couldn't keep it from her—she knew Vance had called everybody into his office, and as soon as they came out she and Ducky had been there, wanting to know why. Ducky had been staggered, but Abby had taken it surprisingly well. Suspiciously well. Barely more than a "Wow, that's crazy" and an "I'm really gonna miss you guys. Keep in touch, okay?"
McGee made his way down to her lab the first chance he got. He hadn't even rounded the corner when he heard her breathing, quick and uneven, like she wasn't getting enough air.
As she came into view he saw her leaning against her desk, her arms clasped tightly against her chest. "It's not working," she said, with a little choking sob. "It's not working."
"What's not working?" he asked.
"Trying to regulate my breathing. Like in Signs. It's not working."
"How's this?" McGee moved behind her and put his arms around her. "In," he said quietly, taking a deep breath, "and out," he exhaled. He held her until her breathing slowed and her body relaxed, until the hyperventilating turned to tears.
"How could he do that, Tim?" she asked, leaning back into him. "How could he take everybody? And today?"
He had no answer, so he said nothing.
"All that time I wasted resenting Ziva for not being Kate, and missing out on some really terrific cooking...and she's only here a year longer than Kate was. And Tony? He's been here so long I can't imagine life without him."
"I'll still be here."
"You'll be in Cyber Crimes. You won't be working with me anymore."
"Are you kidding? I'm definitely going to need your help."
Abby released a shaky sigh. "Really?"
"Really." He gave her a slight squeeze, but she pulled away and turned to face him, her eyes growing panicked again.
"Yeah, well, maybe for now, McGee. Until you get tight with your new buddy Holsworth. Until you get transferred." Her voice was rising and rising to a more hysterical pitch. "Until you get killed."
"Abby, I'm not going to...."
"Do you think Kate planned to get killed? Or Agent Cassidy? Or Director Shepard?"
He held up an imploring hand. "You once told me that you needed me to be okay if something ever happened to you," he said. "Well, now I need the same promise from you."
She frowned stubbornly. "No."
"What? You have to...."
"I don't have to do anything." Her hands began moving frenetically, her nails clicking as she brought them into contact over and over again. "Don't you go dying on me, Timothy, I can't handle another one."
"I'm not...."
Tears were streaming down her cheeks and her breathing was quickening again. "I can't...I can't...."
He stepped forward, took her face in his hands, and kissed her. She wrapped her arms tightly around his neck, threaded her hands through his hair, kissed him back, and even without the taste of salt he could have told that her heart was breaking in half.
They separated, rested their foreheads against each other.
"I know you want...."
"Ssshh," said McGee. "I'll worry about that."
She nodded, hugged him tighter.
"I'll worry about everything."
"You shouldn't have to."
"I don't," he said.
They stood together, breathing in perfect synchronization.