Disclaimer - see chapter one

A/N: I am not a crime scene investigator nor a scientific person. I have done my best with the forensics in this chapter, please forgive me for any errors.

Chapter Eleven - The Case

Nick had barely got through the first line of "I Will Survive" when Grissom's cell phone rang and the nightshift had to leave the party. To their relief. Ensuring the radio in the Tahoe was switched off, they drove to the crime scene.

On arrival they were greeted by Brass who, after being introduced to the temporary addition to the team, explained what he knew so far. Two bodies. Both with gun shot wounds. One male. One female. Both in their twenties. Called in by a neighbour who heard shots fired.

Grissom dispersed the team and, taking Catherine and Horatio with him, entered the apartment building. They proceeded up the stairs to the second floor and headed for the group of police officers.

"Whoa!" Catherine exclaimed as she suddenly grabbed hold of Horatio's arm. "What the hell is on this floor?"

"It's been recently polished," a police officer explained as he walked to greet them.

"Shouldn't there be a sign up or something?" Catherine frowned as they all walked to the apartment doorway.

"Who polishes a hallway on New Year's Eve?" Grissom asked suspiciously.

"A bored cleaner apparently. She had nothing better to do. She saw the victims arrive together just after she had finished."

The police officer was just about to step into the apartment, but Grissom stopped him. Opening his kit he took out slips for their shoes.

"Polish," he said. "We're gonna need to know how many people were in this apartment tonight. We don't need our shoes adding to the confusion."

Turning to another officer he gave the instruction that no-one was to enter the apartment without first covering their shoes, and the three CSIs entered the scene of the crime.

"They're in the bedroom," the officer informed them.

Catherine looked to Grissom and raised an eyebrow. A man and woman dead in a bedroom. Usually a crime of passion.

They surveyed the rest of the apartment as they made their way to the bedroom. No sign of a struggle. Through the bedroom door they saw the woman was lying on the bed, the man on the floor. And they processed the scene.

~The Evidence~

As Grissom had expected, there were traces of polish on the carpets, allowing them to lift several sets of footprints. After eliminating those belonging to police officers, they were left with three sets. One the woman's, one the man's, the other, the suspect's.

The three CSIs stood looking at their diagram of the bedroom and the footprints.

"So this person enters and leaves. Suspect. This person enters walking directly to here -" Cath said as she drew a circle on the diagram around where two sets of prints were facing each other. "And she seems to start here and walk along the same line that he took to come in, to leave, and also walk from here to the bed. But she never enters the room."

"Hmm. She starts twice, from the same spot, opposite the door that she never came through. That implies that she was already in the room." Grissom mused.

"But the cleaner saw her come home, and how would she have got polish on her shoes?" Catherine asked.

"Exactly."

Whilst they had initially thought that finding footprints was going to give them somewhere to start, it was causing them a great deal of confusion.

"What else do we know?" Grissom asked.

"Both victims were shot. The male was hit over the back of the head first, but cause of death was the gunshot. Nick and Sara are talking to the neighbours with Brass, see if anyone saw the other person.. I can guess what they're gonna find out." Catherine stated.

"Really?"

"It's her boyfriend. The male victim was her lover."

"And what makes you say that?"

Catherine shrugged her shoulders, "Just a theory."

"Since when do we work on theories?"

Catherine turned to Horatio and smiled. "I was just saying."

Grissom watched Catherine's smile suspiciously. Her and Horatio seemed to have unspoken communication. He and Catherine used to have that, but lately it had felt like all communication between them had ceased. They were drifting apart. Was it because of the friend she now had in Horatio Caine? He was gazing at her. He had been for seconds, when she turned in his direction and noticed. He looked away quickly.

"So these footprints - "

Catherine smiled to herself, yet it was a smile of puzzlement. What was going on?

"What about the other room?" Grissom continued, composing himself.

"Well ,our victims enter along the same route. The third prints follow the walls to the bedroom door."

"That doesn't look suspicious," Horatio commented sarcastically.

"Do we know who entered first?"

"Our male vic's prints overlap the female's. As for the others, we don't know. We do know that she met herself coming the other way though." Catherine smiled.

"She turned round. She walked into the bedroom backwards?"

"Best explanation I can think of."

"So now the question is why."

"Maybe the boyfriend'll be able to tell us. Let's hope they've found him."

Luckily, they had. Sara called to say that several neighbours had given the same name for the boyfriend, and they had tracked him down and were bringing him in.

"Had you already spoken to them?" Grissom asked Catherine in the car on the way to the police station.

"No! You know, in some places theories are considered a good starting point. And seeing as mine was right, I think you should think about that."

"So what's your theory on what happened?"

"Well, it seems pretty obvious. He found them together and killed them. The evidence supports it. They were all there, now two of them are dead."

"We don't know the boyfriend was the third person."

"But we will."

"It wasn't exactly the most difficult theory to come up with."

"I know," she smiled, "I think it's not exactly the most difficult case. It's a crime of passion, spur of the moment, it wasn't planned, wasn't calculated."

"So why'd he sneak along the walls?"

"He heard noises coming from the bedroom. He was being cautious. He grabs his gun and sneaks in."

Grissom just looked at her, an unsure expression on his face.

"It's just a theory," she added.

"We'll see."

~The Confession~

"He's what?!" Grissom almost yelled at Brass. The detective had been waiting for them, his talk with the boyfriend was over, and had surprising results.

"He's confessed," Brass repeated.

"To what, exactly?" Grissom said in a quieter, calmer tone.

"To killing Jackson Flynn. He says it was self-defence. He walked in, Jackson had Tina pinned up against the wall with a gun at her chest, and he shot her. Then he turned, so he hit him unconscious, took the gun and shot him."

"Then ran."

"He said he moved Tina to the bed, tried to revive her but he couldn't, then he realised he'd killed Jackson and ran."

"He's got it all planned," Catherine said, much to the surprise of the others who turned and looked at her, awaiting her explanation. "What? He blames the dead guy for killing his girlfriend, he can't argue, so he can claim self-defence and he thinks by confessing it gives his story credibility. And by the looks on all your faces, he was successful," she shook her head, "you all believe him because he's the one who was cheated on."

"Cheated on?" queried Brass, "There was no mention of his girlfriend cheating on him. He said he'd never seen Jackson Flynn before. He must have been an intruder."

"His girlfriend's infidelity would give him motive for murder. He's not gonna give up that piece of information, is he?"

"True. So if your theory is correct, you will have to start looking for evidence to prove he's lying," Grissom said, smiling to Catherine.

"I will have to?"

"It's your theory. Run with it. You can take charge."

"Why?" she asked suspiciously.

"Because you seem more in tune with what's going on here than I am. And it'll be good practice."

That comment caught the attention of the younger CSIs. Practice for what? Their shocked looks to Catherine went unanswered though, as she was focussed on Grissom, their eyes locked as both tried to read the other. Unsuccessfully.

"So, not because you wanna see me fail?" Catherine decided to break the silence by changing the subject, something at which she was well practiced.

"Catherine -"

"Sorry. Thank you. Okay, Sara, Nick, Warrick can you go to the lab and check the victims' clothes and all the evidence we have, for anything that indicates the two victims were involved - sexually, romantically, whatever."

"Yes, ma'am," Nick said with a wink, and the three of them left.

"Grissom, Caine, you're with me," Catherine said mischievously. "Brass, can you talk to him again? See if you can get him to slip up."

"Will do. I'll keep you posted."

"So where are we going, Boss?" Grissom said with a cheeky grin on his face.

"We are going to the apartment to re-enact his version of events."

TBC..