A/N: Thanks for the reviews and alerts! Enjoy!

Disclaimer: I do not own NCIS or any original characters.

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The next day, after dropping Aiden and Aaliyah off with Janice, Tony and Ziva had arrived at work. Almost simultaneously with the two of them approaching their desks, Gibbs summoned them to follow him. Obediently, they accompanied their boss to the elevator.

"Where are we going, boss?" Tony asked as the elevator door closed.

"Questioning the other marines, DiNozzo," Gibbs replied. The three of them walked to the car and the ride went relatively quickly with Gibbs driving.

"Special Agent Gibbs. NCIS," Gibbs introduced himself to the marine in front of him.

"We've been expecting you, Agent Gibbs," he said. "Come with me." He led the three agents onto the base and directed them to the people they were looking for.

"This is Special Agent Gibbs from NCIS," the marine was saying, gaining the attention of the other men. "I expect you all will give him and his agents your full cooperation in investigating Davis' murder."

Ziva scanned the men. They all looked like typical marines; although they usually did, whether they knew anything about the case or not. While Gibbs was talking to two marines, Ziva slowly walked around, trying to pick up a vibe from any of them. Her eyes fell upon one man who met her eyes then quickly looked downward, then regained eye contact. That was very uncharacteristic, she observed. She walked over to him and introduced herself.

"Shawn Klein," the marine responded with his own name.

"Can you tell me about your relationship with John Davis?" Ziva asked.

"Believe me, ma'am, the only relationship Davis and I had was strictly professional," Klein replied. "And even that we tried to keep to a minimal."

"We did not get along?" Ziva inferred. Tony and Gibbs had reached Ziva's side after talking to several other marines.

"No ma'am," Klein replied shortly.

"Is there any particular reason for that?" Ziva pressed on. She could tell that Klein was struggling internally on how to answer the question.

"Let's go, marine," Gibbs pressured him impatiently. Klein sighed and blurted out his answer.

"He destroyed my marriage," was the reply.

"How so?" Ziva asked.

"My wife. She..." Klein's voice trailed off as he shook his head bitterly.

"She left you for him?" Ziva guessed. Klein's eyes filled with bitterness and hatred for a quick moment, but he hastily covered his emotions.

"No, ma'am," he replied in a semi-strained voice. "She slept with him. She admitted it to me that it happened one time, but I know it has turned into a full out affair."

"How do you know that?" Ziva asked. Klein's jaw tensed up, and his eyes were glistening with hatred as he thought about Davis and his wife.

"I just do," he replied through clenched teeth.

"We're gonna need you to do better than that," Gibbs said. Klein looked back and forth between Gibbs and Ziva before taking a deep breath to cooperate.

"Okay. A few months ago, I noticed Crystal was acting strangely. She wouldn't make eye contact, stuttered a lot, you know, and showed other signs of cheating," Klein began. "I confronted her about it. She admitted that she slept with John Davis once. I assumed that she had been acting strangely toward me because of the guilt, and once she admitted it and we moved past it, I thought things would go back to normal."

"They did not?" Ziva asked. Klein shook his head.

"We never moved past it, ma'am," he replied. "The one hook-up turned into an affair."

"Well that's just an assumption unless you can give us any proof," Tony said, breaking his silence, and annoyed that this marine was refusing to reveal why he thought his wife and Davis were having an affair.

"It's not an assumption, sir," Klein insisted bitterly. "I have driven past his house before and Crystal's car was there when she was allegedly shopping or at the gym or with friends. There have been times when I'd walk into the room she was in and she would be on some secret phone call and would hurry up and hang up when she saw me. She texts a lot and deletes them immediately. She's clearly hiding something from me, and I know it's an affair with Davis." Tony nodded as Ziva wrote down information from their interview.

"Well those certainly are good indications," she observed.

"Yes, ma'am," Klein agreed. "That's why I couldn't stand him."

"You must really have hated him," Ziva concluded. Klein nodded.

"I did ma'am," he admitted. "But I always pride myself on being a marine before anything else. I didn't let my personal feelings for him affect us professionally."

"That's very admirable," Ziva said.

"Yes, ma'am," Klein nodded. It was silent for a moment as Ziva pondered how to ask her big question. It had to be asked.

"Where were you two nights ago when Davis was killed?" she asked. Klein looked stunned. Apparently, he had thought that he had cleared his name.

"You really think I killed him, ma'am?" he asked.

"You did have an awful lot of hatred toward him," Tony pointed out.

"Yeah, but I just told you I keep things professional," Klein said defensively.

"Yes you did," Ziva agreed. "Now, where were you two nights ago when Davis was killed?" Klein shook his head silently, a look of bitterness on his face.

"Working out," he finally replied. Ziva nodded and wrote down his response. "You want witnesses? Right over there." He pointed toward a couple of marines a few feet away. "Are we finished now, ma'am?"

"For now," Ziva replied.

Gibbs, Tony, and Ziva left and were driving back to headquarters discussing what they had learned. It was obvious that Klein had disliked Davis for legit reasons, especially if his wife truly was having an affair. However, the men that Klein had said he was working out with had vouched for him. The case was beginning to get interesting.

"Maybe Klein's wife really was having an affair with Davis," Tony suggested. "Then maybe Davis' house found out about it and killed her husband."

"It's certainly a possibility," Ziva agreed. "Many women have killed their husbands for cheating."

Gibbs parked the car and the three of them arrived back at their desks. Gibbs instructed McGee to get Davis' wife's name and home address. In a matter of seconds, McGee had the information.

"Tony, Ziva," Gibbs began, turning toward them.

"On it, boss," Tony said. He grabbed the car keys, and he and Ziva left to question John Davis' wife.

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A/N: There's chapter two! I hope you liked it. Please review!