Sorry it's been a few days, I was staying with my grandparents and they aren't big on technology, but thanks to everyone who's reviewed or put me on story alert!

OK, I'm pretty sure I know vaguely where I'm going with this, but I'm open to suggestions about suspects or stuff.

The food was amazing.

Piles of roast and boiled potatoes, beef and lamb and whole chickens, tureens of steaming vegetables, sausages and so much more were heaped on plates. The NCIS team sat at the Gryffindor table with Hermione, Ron and Harry, who, between mouthfuls of food, were explaining about Hogwarts, its houses, and Quidditch, something which Ron and Harry took particular interest in.

"Anyway, I've already talked to Dumbledore. It's been arranged; you'll all stay in Gryffindor tower, with the sixth years. There's extra beds, the guys might be a bit cramped but I'm sure it'll be fine…" Hermione just couldn't seem to stop talking. Ron and Harry's eyes met and Ron suppressed a snort. According to Hermione, Ziva and Abby were to stay with her and the other sixth year Gryffindor girls, and Tony, McGee, Gibbs, Ducky and Palmer would go with Ron and Harry, joining the boys during their stay. Like she'd said, Hermione had it all arranged.

"Hermione," Ron finally interrupted her, "your food's gone cold."

After pudding, the team could barely keep their eyes open. Harry noticed.

"Yeah, the food does tend to do that to you. You'll get used to it."

Together, they departed the Great Hall for Gryffindor Tower. The team trudged after the teens through an endless maze of halls and stairs. The stairs woke them up slightly. Tony got a shock when the step he had just put his foot on disappeared from underneath him, and McGee nearly jumped out of his skin when one of the staircases started to move. Harry, Ron and Hermione seemed to find this perfectly normal, however.

Finally, they drew to a halt in front of a huge portrait of a woman. Another surprise was in store when she moved, settling in her seat, and asked, "Password?"

Hermione swallowed before answering, "The Fallen One."

The portrait nodded grimly, and swung forward, revealing a hole in the wall that the students climbed through. The team glanced quickly at each other before following suit. It seemed the dead girl had belonged to this house.

Once in the common room, Ducky, Palmer and Abby excused themselves to get to work on the body and evidence, respectively. Harry offered to escort them down to the dungeons, which they appeared grateful for. This left Gibbs, Tony, Ziva and McGee with Ron, Hermione, and a room full of curious wizards. A round-faced sixteen year old boy eyed their guns nervously.

"Oh, calm down, Neville, they're not going to shoot you." Hermione laughed.

The tension in the room seemed to ease a bit. Ron turned to McGee, Gibbs and Tony.

"C'mon, I'll show you where you're going to be staying." He lumbered up a spiral staircase, the three trailing behind him.

Hermione watched him go with an unreadable expression, but if Ziva had to guess, it could be described as a furtive look. Tony glanced back at Ziva and grimaced comically, which made her smile. Hermione finally looked at Ziva.

"Do you want me to show you where you and Abby'll sleep?"

"Sure."

The dorm room was nice enough, Ziva decided, but she could really do with having Abby there. She wasn't afraid or intimidated, but it would be nice to have someone there she knew. As soon as she and Hermione entered, three girls hurried over to speak to them, each asking did she know who had killed their friend. Ziva noticed tears still streaked one's face.

"Hold it!"

The voice came from behind them. A girl, slightly younger than the owners of the dorm, with a long mane of dark red hair, stepped inside.

"Ginny," Hermione said in relief.

The girl, Ginny, smiled reassuringly at Hermione, then addressed Ziva.

"Hey, I'm Ginny Weasley, you may have already met my idiot brother, Ron." She introduced herself cheerfully, though Ziva could sense a lot of her tone was forced. It seemed Lavender's death had really messed up their life.

She suddenly realised everyone was looking expectantly at her.

"My name is Ziva David," she said, "I'm a Probationary Agent at NCIS, former Mossad Liaison Officer."

Only Hermione seemed to understand this, however. She gasped.

"You were with Mossad?"

Ziva nodded.

"How ever did you survive?" Hermione asked, and the girls looked at Ziva with new-found respect.

"It's what I'm trained to do." She sighed, "Most of my family were not so lucky."

The girls led Ziva over to a spare bed with sympathetic expressions, and Ziva knew she was cornered, expected to elaborate. If she was to gain their trust, she'd have to tell them.

"My mother and sister died in a bombing when I was about eighteen. I wasn't there, I was serving in the Israeli Army at the time." She paused, as if uncertain whether to continue, but she did, "My half-brother, Ari, I was his Control Officer in Mossad, but he went rogue, went bad. He was shot."

Ziva neglected to mention that she was the one who shot him. "And my father, he's still alive, but – "

The girls noticed her voice had suddenly hardened.

"– He does not care for me." Ziva stopped talking, and it was clear she had finished. She was sitting cross-legged on the bed, but she stood up and removed her NCIS cap. "It's late, you girls should probably sleep."

"Aren't you going to?" Hermione asked, concerned.

"No. Gibbs told me to provide security for you, just in case."

Ziva took her gun out if its holster and checked it over, making sure there was nothing wrong. Once she was sure, she re-holstered it, and did the same for the smaller gun strapped to her ankle. Finally, she took a retractable knife from the pocket of her combats, and checked that, too. When she returned it to her pocket, she found their eyes trained on her, mouths open. She shrugged.

"Rule number nine: Never go anywhere without a knife." She recited. "Don't worry, you'll be perfectly safe."

Meanwhile, in the boys' dorms, Tony was cracking jokes with Ron and a sandy-haired boy who'd introduced himself as Seamus Finnigan. McGee was chatting animatedly with Neville, who looked calmer about their presence now he knew they were friendly. Gibbs and Harry were talking a short distance away from the others.

"Lavender was muggle-born." Harry was saying. Seeing Gibbs' confused look, he elaborated, "Her parents were like you, non-magic. If it were up to me, I'd investigate Slytherin. They're famous for their hatred of muggle-borns."

Gibbs nodded. "We'll be sure to talk to them in the morning. We're going to have to interview all of you, by the way."

"Not a problem," Harry said, "but we should probably get some sleep now."

"Sure," Gibbs said, "but one of us'll keep watch, just in case the killer tries anything."

Again, sorry about the wait.

I've had several story alerts, but not so many reviews, so I'd be grateful if you could leave one, or if you have any suggestions. I know I haven't shown much Tiva, Harry/Ginny or Ron/Hermione, but that'll pick up in the next chapter. I also might add in some McAbby. These first few chapters were setting up the story really.