The next night, Greg arrived at work, well ahead of time, a few people had to do a double take at seeing the spiky haired young CSI in so early, normally Greg was content to dash in at the last minute, a whirlwind of hellos and papers falling to the floor in his wake. The smile on his face, normally permanently attached, was also missing in action this evening, replaced by a steely, grim expression of determination. Nick Stokes almost collided with the young man in his haste to get from the locker room to the lab.

"Hey man where's the fire?" The Texan joked.

"Got to get to work." Greg muttered as he brushed past quickly.

Nick watched stunned, as he stormed out with barely so much as a 'hello', what had happened to happy go lucky Greg?

Sara entered shortly after, also looking a bit downhearted and Nick decided to question her about Greg's mood.

"What's gotten into him?" Nick questioned.

"I think yesterday has badly affected him." She confided.

"Bad one?"

She nodded. "It was awful Nick, really awful, this poor young guy had been tortured, it really shook Greg up."

"Poor kid," Nick sympathised. "He was only just really getting into his stride as a CSI, I'm sure this is the kind of case that will drive him back."

"No actually," Sara said. "Quite the opposite in fact, he's taken it upon himself that he must get the evidence to get this killer. I've never seen him like this before, I'm quite worried about him to be honest, I think he may be taking on more than he can handle."

Nick was immediately concerned too, he knew what could happen when you got too personally involved in a case, and this seemed to be a such a big one too. "Where is he now?" He asked.

"At the autopsy with Doc Robbins, I'm just on my way there myself." Sara said as she finished changing.

"I'll have a little talk to him later." Nick promised.

"Thanks Nick, I'd appreciate that." She smiled at him, as she slammed her locker shut and made her way out.

When she entered the autopsy room, Greg was stood already listening intently to every word the Doc was saying, there wasn't a hint of repulsion on his face, like the last time he had faced this body, just a serious expression that definitely showed he meant business.

"The cause of death," Robbins was saying, "at first looks difficult to distinguish, given all the injuries, but I am satisfied and in a way quite glad to say that most of these injuries were actually obtained post mortem."

"Really?" Greg was surprised and relieved that perhaps Callum hadn't suffered as much as he initially thought.

"The COD was exsangunation caused by the single gunshot wound, it punctured the left ventricle of the heart and he bled out, the stab wounds and the bruising all happened post mortem, to shatter the bone like that here on his left leg," Robbins indicated the damage to the CSI's. "I would say this was done with a claw hammer." He said, with a little shake of the head.

"What a brute." Greg muttered, the disgust he felt evident in his voice.

"Is there any sign of sexual assault?" Sara asked.

"None whatsoever, there is no evidence that the victim even had consenting sex in the hours before he was killed." Robbins revealed.

This puzzled the CSI's somewhat, it seemed from the state of undress the victim had been in, that the motive was perhaps sexual, now this was ruled out and robbery wasn't a valid option either, what other motive could there be?

"Did you find anything else?" Greg asked hopefully.

"Just this, it was embedded in his belly button." The Doc said holding something up with a pair of tweezers, Greg and Sara both squinted to look at it.

"What is that?" Greg asked unsure.

Sara spotted what it was immediately. "It's part of an acrylic nail." She said, surprised.

"But I thought the victim didn't have sex?" Greg stated, Sara nodded gravely and suddenly Greg understood, his face rapidly paling. "Oh god, you're telling me that a woman did all this?"

"It all adds up Greg, the lipstick imprint on his cheek, the position he was found in, the nail embedded in his skin, a cheated lover perhaps?" Sara theorised.

Greg shook his head, wholly unwilling to believe a woman could inflict such violence, he had been convinced it was some psychopath brute killer not a woman!

"Hell hath no fury like a woman scorned." Robbins commented, looking over the mutilated body on his table. "Do you think it's interesting she left the face untouched, just the lipstick, some kind of message perhaps?"

"Possibly," was all Sara could say, they thanked the doc for his work and headed back to the lab to examine all the evidence they had to track down their vengeful female.

This was going to be a very difficult case to crack, Sara realised as she and Greg were on their way to Taboo, the place Callum was last seen. Greg was sullen and quiet in the car, it was unnerving to see him like this, normally he was chirpy and talkative when they were driving around, she had never seen him so serious. "Are you Ok Greg?" she finally asked after 25 minutes of solid silence.

Her blond co worker continued to stare out the window passively, not even hearing her.

"Greg!" She tried again, louder to get his attention.

Greg jumped up slightly in his seat and glanced over at Sara. "What? Did you say something Sara?"

Sara sighed. "I asked you if you were OK, you've seemed out of sorts since we found that body." She explained.

"I'm fine." He shrugged off none too convincingly.

"Greg," She struggled to find the right words, "I just think this might be too much for you to deal with at the moment."

He immediately became defensive and rounded on Sara "Are you saying that this case is too big for me and I can't cope with it?" He looked hurt and angry at the suggestion.

"No Greg it's not that, it's just you're getting really worked up about this and I know how disappointing it can be when things don't work out." She replied, keeping her eyes on the road.

"Well there won't be a disappointment because I will nail whoever did this!" Greg declared.

It was a good job Sara was driving or she would have seen the hot tears at the back of Greg's eyes, she decided to drop the subject and have a word with Grissom later.

The club was heaving when they arrived and met up with Captain Brass, with many revellers casting wary glances at their CSI vests. Sara and Greg fought their way to the bar with Brass and flashed their credentials at the bar manager. "Sir we'd like to ask you a couple of questions." Brass said, taking charge "Is there somewhere we could chat in private?"

"Sure," the man quickly ushered Brass and the CSI's into his office, shutting the door firmly.

"What is this about?" He asked, once they were out of the earshot of customers.

"Mr Silverman, we are investigating the murder of a young man and we believe this is the last place he was seen alive on Christmas Eve." Brass patiently explained.

"Do you recognise this man?" Greg asked, thrusting the photo of Callum at the manager.

Mr Silverman looked at the photo closely, "Yeah, vaguely, listen loads of kids come here, they all look the same to me" he shrugged.

"Is there a 'Melanie' working here tonight?" Sara asked, "the victims receipt showed he was served by a Melanie that night."

"Er yeah, sure Mel's out there now." He said, not entirely sure how he could help these CSI's. "I'm not sure how much of a help we can be." He admitted to them.

"Mr Silverman, we believe that Callum met his killer here that night, it's possible someone could remember who he was with, with your permission we would like to issue his photo around and see if it jogs anyone's memory." Sara explained.

"Sure," Mr Silverman said, "Just don't tell them the reason why you're doing it, the last thing this club needs is bad publicity."

"No problem." Greg smiled at him, as he and Sara got up and to the task of issuing his photo. Sara went to chat to Melanie first.

"I need to know if you recognise this man at all." She after she had located the blond waitress "I know this must be difficult," she apologised "I know you see hundreds of people."

Melanie took the photo from Sara "No, I do remember him actually, him and his buddies come in quite regularly, nice kid, tips well, is he in some kind of trouble?"

Sara hesitated "We're just trying to establish his movements on Christmas Eve."

"Oh!" Melanie said "Yes he was here, he left with some girl."

"Do you remember anything about what she looked like?" Sara pressed.

"No I'm sorry." Melanie said, "I didn't really get a good look at her."

"Thanks." Sara said, now they had confirmation he did meet a woman here, they could check the security tapes.

Greg meandered his way around the club, not really getting anywhere, nobody had anything really significant to add, he was showing the picture to a pretty redhead when a man walking by stopped, exclaiming "Hey that's Cal! What do you want with Cal?" He addressed the CSI.

Greg exhaled, "Sir could I talk to you out in the foyer?" he said, really not wanting to reveal the details of the murder in front of a packed nightclub.

"Sure" the man shrugged, not really understanding why CSI would be asking after Callum

"Is he in some kind of trouble?"

Greg tried to be as tactful as possible once they got away from the busy main room.

"I'm sorry to say that Callum is dead." He said gently.

"Oh god!" The man's face whitened."How? When? I don't understand!"

"I know this is difficult for you to take in right now," Greg said keeping his voice calm and steady "but Callum was murdered and we need your co-operation to find the person responsible." he said firmly.

The man couldn't believe what he was hearing "Murdered! But he was right here on Christmas Eve, we all were, he was alive! This can't be happening, he was my best friend." The man was obviously becoming distraught, Greg laid a comforting hand on his shoulder. "I'm so sorry." He said sincerely.

"And I'm sorry to do this to you now but would you be able to answer a few questions on Callum's final hours, it would really help the investigation." He added.

"Okay." he managed to utter, still in a complete daze.

Greg ushered him into see Brass, "This is Callum's best friend Michael Nelson." He explained quietly.

"Mr Nelson, I'm sorry," Brass said "but I need to ask you a few questions about what happened Christmas Eve."

Michael nodded that it was OK so Brass pressed forward.

"Is there anything at all that you can think of that was unsual that night? Did Callum speak to any strangers?"

"I don't know." Michael answered honestly "We split up quite early on like we always do, Callum was a bit of a flirt."

"Has Callum had a girlfriend recently that you know of?" Greg interrupted before he could stop himself.

"Girlfriend? No, Callum wasn't really a girlfriend kind of person if you know what I mean man, he was just out for what he could get. A real ladies man. Christmas Eve wasn't any different, he has this uncanny knack of pulling real fit women, that girl on Friday was an absolute knockout."

Both Brass and Greg sat up a little straighter at the first mention of a girl.

"Did you recognise this girl that Callum was with on Friday?" Brass probed.

"Never seen her before in my life, trust me if you'd met this girl before, she's not someone you would forget in a hurry." He said specifically addressing Greg, Greg nodded his head in understanding.

"What can you tell me about the girl?" said Brass abruptly, perhaps slightly annoyed that Michael felt he couldn't relate to beautiful women. He saw Sanders suppressing a smirk.

"Oh wow, erm, really curvy, killer cleavage you know," Michael said, again directing his comment toward Greg " She had super glossy hair, the kind of woman you spend your whole life dreaming about." He became quite wistful for a second, before remembering his murdered pal. "Wait you think this chick had something to do with Callum's murder?" he asked clearly astonished.

"At this stage she is the prime suspect." Brass acknowledged. Michael's jaw dropped "No way!" He muttered "no friggin' way."

Brass and Greg left Michael and headed to the security office where Sara had obtained the security footage, they took it back to the lab for Archie to examine, Greg was so eager for their first glimpse at the killer bitch, he raced straight to Archie's lab when his work was done.

"Got the femme fatale yet?" He asked his tech friend grimly and without humour.

"Er well no," Archie admitted forlornly. "Take a look for yourself."

"Here is December 23rd footage," he said "not what we're looking for but it's clear." he clicked his mouse to bring up a new window "and here is December 24th."

Greg watched as the screen erupted into a blank wall of nothingness and then black and white fuzziness, then jumped briefly to the bar, before back to fuzziness, all that was visible on the recordings was the time stamp.

"I tried everything I could to clear the pictures up," Archie said apologetically "but it's not the tapes, it's the footage it was sabotaged before the cameras even started recording that night. Whoever she is, she's good."

"Thanks anyway." Greg said dejectedly, trooping off to tell Sara the bad news. Pushing open the break room door, he announced with despair. "Security footage was wiped."

"Shit." Sara responded.

"Shit indeed!" said Greg, angrily sinking into a seat at the table "We have no suspect, no leads, no nothing!"

Greg was so visibly downhearted, he desperately wanted to bring Callum's killer to justice.

"I know you're desperately disappointed Greg but this is very early days yet, something might come up, don't give up hope." Sara said kindly. Greg remained silent, sat staring vacantly at the table.

Sara grasped his hand gently to try gain his attention. "Greg is something bothering you? I've never seen you so worked up over a single case before. Actually no, you don't have to tell me." she said seeing his shoulders sag visibly, he looked like he was about to burst into tears. She gripped his hand more firmly.

Greg 's fingers curled around hers, grateful for Sara's support, perhaps now was the time to tell?

"It's OK." He said, giving her his full attention now. "If I tell you something will you promise not to tell the others?"

"You have my word" She said, knowing in her heart, she might not be able to keep that promise dependent on what Greg was about to tell her.

"I should have told you about Luke ages ago," He started "but I'd buried what happened to the deepest part of my brain." already he could feel tears pricking at his eyes as he thought about Luke and wiped away furiously with the back of his free hand.

"Greg, if this is going to be difficult for you, you don't have to do this." Sara said gently.

"No, it's OK, I'll tell you." Greg said steadily, his tears now gone. "Luke was my room-mate at college, my best friend in fact. Luke was probably the complete opposite of me, he was sporty, I was a chemistry geek, he was a flirt, I was very shy but somehow we clicked you know." Greg smiled at Sara in memory of his friend and Sara nodded in encouragement, still tightly gripping Greg's hand.

Greg's eyes darkened as he recalled the most horrendous night of his young life at that point.

"One night, after a party, while we were both sleeping in the dorm, somebody broke in, Luke woke up but I didn't." Tears had now formed in Greg's eyes again, threatening to spill. "They, they had a knife, the person stabbed Luke over and over again, he must have been terrified, but I never woke up, can you believe that? My best friend was being attacked and I couldn't wake up."

Sara sat horrified as Greg relayed the terrible story, she had had no idea.

Greg continued bitterly."They think I was drugged somehow to ensure I wouldn't wake up, the killer wasn't interested in me, only Luke. When I finally woke the next morning, the sick bastard had put him back into bed so it looked like he was sleeping. I was so wrapped up in my own world, so desperate to get to my lecture that I never even checked him, never saw the tell tale tiny droplets of blood on the floor!" His voice became angrier and choked up.

"Greg, I don't know what to say" Sara began uncertainly, Greg ploughed on anyway.

"They never did catch the killer, said there was not enough evidence, a rival jock of his was arrested but he had a watertight alibi. In truth, any number of people could have killed him, the police were absolutely clueless and then somebody came to my room to do a forensic search. He was a CSI, I still remember him Rob Matthews, nice guy. I bugged the hell out of him, asking him questions at every opportunity about forensics. I was absolutely fascinated by him, how the smallest amount of DNA, a fingerprint, a blood drop could solve a case, but Luke's was never solved. We had his funeral, memorial service and then life went on, people chose to forget about the fact a student was murdered on campus. But I never did, never forgot Luke's memory, suddenly I had a new career path to aspire to. I talked to Rob again when I finished college, told him what I wanted to do, and he told me there was a position available as a DNA analyst, he recommended me before he retired, it was my first job"

"Im so sorry Greg, that's a terrible thing to go through" exclaimed Sara, her heart aching for Greg.

"I've tried to forget about it, that awful night" Greg confessed "but I've never forgotten about Luke, I like to think what I'm doing now, being a CSI, I'm doing it all for Luke, but Callum's murder scene, all that blood, all I could think was being reminded of my 19 year old self, helpless at a young boy's life being snuffed out like that again! Luke's killer was never brought to justice but I'll be damned if Callum's killer gets away with it, not now that I can do something about it" His voice shook with emotion and Sara immediately enveloped her friend in a hug.

"Greg I'm so sorry for what happened to Luke but you can't make this your one man mission, we're going to work on this together" she told him firmly

Greg smiled gratefully at Sara "I won't drop this case until we have Callum's killer" He told her resolutely. Sara hugged him close again, she could only hope for Greg's sake they would be successful in their pursuit.