CTU Los Angeles, Los Angeles

Chloe O'Brian had never experienced such a day like this and she knew that it was far from over. She had only worked at the LA branch of CTU for a short time, but had hoped that she wouldn't have to face such a major threat so soon. Stories of the events a few years back had been told to her even though she had never asked. Walking briskly down the dark corridor towards Tech One, eager not only to stop Nina Myers' worm but also to defeat someone who thought they could mess with her computer system, she didn't notice the person following close behind her until they knocked against an exposed pipe.

"Is there anyone there? I don't have time to be playing games!" Chloe snapped as she stopped for a moment. Sighing, she continued her brisk walking and, as she was about to turn the corner into the well-lit area around Tech One, a hammer was brought down hard onto the back of her head, sending her crashing to the ground. The attacker and would-be murderer of Chloe O'Brian then dragged her body into a nearby deep alcove, before they took a deep breath and smashed the hammer down onto her head once more. Listening out for any breathing or signs of anyone likely to discover the grisly scene, the attacker silently left the alcove and had soon disposed of the hammer in a nearby air vent. Luckily for them, the attack had left no traces of her blood on their clothes.

In Tech One, Adam Kaufman was distracted as he tried his best to defeat the worm. He kept looking over at the door and expecting Chloe to walk through it, but there was no sign of her. Whilst he wasn't a fan of her personality, he had a deep respect for her work and ability to do almost anything with computers and so he knew very well that if she wasn't in the room as soon as possible, the worm would complete it's deadly work and hundreds of undercover CTU agents would be at risk. Cursing under his breath, he grabbed the phone and dialled Tony's number.

"Tony, where's Chloe? We're running out of time!" Adam spoke as soon as Tony replied, his eyes fixed on the door.

"She's not there yet? She left the bullpen ten minutes ago!" Tony replied, his own eyes scanning the large bullpen. Noticing a guard approaching him with a shocked look on his face, he asked Adam to hang on for a moment. The guard seemed eager not to broadcast whatever he needed to say.

"Director Almeida, can you come with me, please?" The guard spoke nervously, and Tony could only wonder what had shook him up so much.

Sat at his desk, Alex Myers watched as Tony and the guard left the bullpen and took a deep breath. The worm was close to succeeding and Nina was minutes away from either being taken back to Mexico or being brought to CTU and a high risk of being killed. He gazed at the blank screen of his hijacked computer and tried to think of what the options were. If Nina were to be let loose in Mexico, it was a certainty that Jack would chase after her almost immediately after the virus threat was over. If she was brought back to CTU, then anything might happen. He glanced over at Kim and wondered what was going through her mind. Jack had been able to get her a job at CTU, and only months after starting she was doing well in the middle of a crisis that involved her mother's murderer.

Tony stared in shock as he tried to process what he was seeing. He was looking at the dead body of Chloe O'Brian and for a moment he forgot about the virus, about Nina, about the worm. Crouching down, he gently closed Chloe's eyes.

"We'll find whoever did this to you, Chloe, I promise," he whispered.

Jack and Nina's plane, above Southern California

"What?" Jack rasped into the phone as he was told of Chloe's death. Unable to believe what he had just been told, he sank into a seat close to Nina, who was watching with some curiosity. She had heard Jack speak only that one word during the call, and she could only guess what it was about. As Jack ended the call, he stared at the opposite wall of the plane and Nina debated with herself whether to ask him about it or not. It didn't matter soon enough, as Jack noticed her looking at him.

"If you don't stop that worm right now, I swear I will kill you right here, no matter what," Jack whispered dangerously, staring straight at her as he spoke. Nina frowned in response, before turning away and looking at the laptop. Seconds later, she returned her gaze to him, and she could see he was ready to jump out of his seat and beat her to death.

"What was the call about, Jack?" She asked, and quickly realised that it was a mistake as Jack did indeed leap out of his seat, before grabbing hold of her neck tightly.

"Someone inside CTU murdered Chloe O'Brian, a good agent who was our best chance of stopping the worm. Now, you wouldn't happen to know anything about that, would you Nina?" Jack spoke with his face close to hers, his voice low and threatening. The look on her face told him that she didn't have any idea about it, but he didn't relent.

"Jack, whoever did it wasn't doing it for me! Look, we can both still get what we want out of this," Nina replied, her eyes staring straight into his.

"Nina, right now I need you to stop that worm, and maybe then we'll see about what you want out of this!" Jack snarled before a beeping sound from the laptop caught his attention. Letting go of her neck, he turned to the computer and saw the message that had appeared on the screen. Yelling in anger, he almost started beating the hell out of Nina, his eyes staring wildly at her.

"Do you realise what you're doing, Nina?!" Jack screamed at her, and Nina tried hard to think of something she could say that would calm him down. She noticed Chase Edmunds walk up to him, but even he seemed fearful of Jack. Moments later, she had decided that it was better not to risk things getting worse, and so she began typing away on the laptop.

CTU Los Angeles, Los Angeles

Tony had gathered the agents and staff together in the bullpen and, as he informed them of what had happened to Chloe, he looked around the crowd and their faces. He was hoping to see a flicker of guilt or look of shame, but he found none. At that moment in time, he had no reason to suspect anyone in particular and he couldn't even be sure that the killer was still in the building. As the crowd dispersed, all he could do was wait for more information from Forensics.

Sitting back down, Alex looked over at Tony and wondered whether they would be able to find any evidence of the killer's identity, before he noticed his screen flickering back to normal. It looked, as far as he could tell, that the worm had been defeated and so his sister was almost certainly going to be back at CTU.

Jack and Nina's plane, somewhere over Southern California

Nina sighed quietly. She had been forced to stop her worm and now she was on her way back to CTU for the first time in three years. She couldn't help but wonder who had killed the agent and if it had anything to do with her or not. Gazing at Jack as he approached her, she wanted to roll her eyes or glare at him, but decided against it. As she handed him the laptop, she still looked at him with a look of hatred that she knew he would never have dreamt of seeing back before she was exposed. Once they had been close friends and even lovers at one point, but now they had gone to a dark extreme and were the worst of enemies.

"We'll be at CTU soon enough, Nina. If you tell us where Alvers and Amador are, I'll consider getting you some sort of deal, understood?" Jack spoke, his voice now much calmer than it had been. She nodded in response, knowing that she had to be patient and wait for the next opportunity to arise, something that she wasn't likely to find on a moving plane. As Jack left her alone with her thoughts, she contemplated the information that she had received about CTU since the surprise and mutually unwanted reunion with Jack earlier that night. She considered what sort of deal she would get if she gave up any of the information she had on Alvers and Amador. Even the sweetest deal would involve a lengthy stay in prison anyway, leaving her a sitting duck for anyone who thought she was too much of a risk sat in a cell.

As Jack sat down, he allowed him a small smile as he looked at the laptop and saw how close it had been. One thing he was sure about was that he had no intention of giving Nina anything in return for any information she gave them.

CTU Los Angeles, Los Angeles

Tony had confirmed that Jack and Nina's plane would be landing soon, and that Nina was to be interrogated as soon as she was brought to CTU. Alex knew that his sister was running out of time, and felt helpless about it. He couldn't stop the plane from landing or stop Jack from bringing Nina to CTU, but he hoped that he could at least stop Jack from killing her. Glancing over at Kim, he wondered just how she was going to react to seeing her mother's killer for the first time since that awful day.

Kim herself was nervously awaiting the return of her father to CTU. It was bad enough that he had been forced to go back under with the Salazars without the fact that he and her boyfriend were stuck on a plane with Nina Myers. The last few hours had been terrible, made even worse by Chloe's murder, and she wondered if the killer was amongst the numerous people working in the bullpen and why they had done such a thing. Certain that it was because of the worm, she considered the possibility of there being a mole inside CTU.

Morris O'Brian had left home almost as soon as he had been told of his ex-wife's death, and now he was standing next to her body in the morgue, silently crying as he held her small, cold hand in his own. He was trying his best not to lose it, but it was proving difficult with every second he spent gazing at her face. He was glad that the guard was stood outside, leaving him alone with Chloe.

"God, Chloe, I didn't think you would die before me, sweetheart. I thought the drink would kill me long before, but now I wish I had never touched a single drop. I've lost you once more, Chloe, and I will never find you again and I don't know what I can do about that. I wish I could go back in time and not make the same mistakes," Morris whispered, before closing his eyes for a second. Opening them again, he kissed her forehead before gently placing her hand back on the table.

"Goodbye, Chloe. I promise never to go back to the way I was," he spoke before he walked away.

Back in the bullpen, all of the attention was on Jack and Nina as they entered the building and headed for the holding rooms. Nina stared at Kim as she passed by, before noticing her brother stood nearby. Alex stared straight into her eyes, and he wondered if Nina could tell something from his face that nobody else could and if she did, that she kept it to herself.

The interrogation had been going for some time, and Alex had now joined Michelle in the surveillance room. He watched closely as Tony questioned Nina, looking directly at Nina's face. She seemed so confident, so defiant and Alex knew that they would likely be resorting to torture soon enough.

"Do you think she knows anything useful?" Michelle asked him, her own gaze directed at Tony, who looked stressed, angry and troubled by thoughts of the day Nina's treachery had been uncovered.

"I don't know," Alex replied before he noticed someone walk into the room with a silver briefcase, and he knew that the torture was about to begin. Whether it would be effective was unknown, even accounting for the fact that it rarely got results, Nina was not easily broken by it. She had been tortured numerous times after her arrest, but she had given them almost nothing by the time she was pardoned.

"What sort of deal could we even offer her if she talks? I can only see us giving her life without parole rather than death," Michelle spoke. She had seen Jack's face as he told her of Nina's pardon all those years ago, and she knew for a fact that any deal this time would certainly not be anywhere near as generous as the pardon had been. If anything, she felt that Nina would be lucky to get anything better than a week on death row before being executed.

In the bullpen, Kim was watching the interrogation via video link. It wasn't that she particularly wanted to watch what was going on, and she certainly wasn't enjoying it, but she felt the need to witness it, to hear for herself what Nina did or didn't say. She avoided looking at her too much but felt herself being pulled towards her face anyway, a strange compulsion to do so overriding her hatred of Nina Myers.

As the needle was pulled slowly out of Nina's neck, she winced quietly and braced herself for the next painful stab. She heard Tony ask her if enough was enough, and she decided that she had to do something drastic in order to open up a window of opportunity.

"This should be enough," she stated flatly, before forcing her head violently onto the waiting needle, slashing through her carotid. Horrified, Tony was shocked at the sudden act and with her blood splattered all over him, he hoped that Medical could do something to save her life. Not that he particularly cared about her, but if she had valuable information then her life was equally as valuable at that time. Alex, who had now entered the holding room, had watched with horror and now he felt helpless as he saw his sister's life beginning to slip away.

Nina was trying her best to retain consciousness as she listened to the panic surrounding her. She could hear Tony's voice, the noise of brisk footsteps and she could feel the warm hands of a woman holding her head, and she wondered if the woman knew what she had done. As she was carefully lifted onto a stretcher, she looked up at the ceiling with her eyes partially closed, the lights merging together into one fluorescent line as she was rushed towards Medical. Soon enough she was lying on an operating table and the noise around her changed from frantic federal agents to medical talk, and she knew that her chance was about to arrive. Squeezing the tubes that were supposed to deliver anaesthetic to her body, she closed her eyes and waited for them to at least stop the bleeding. Moments later, she had opened them again, grabbed a scalpel and had leapt from the table to kill all but one of the medical staff. Wasting no further time, she made her way down a dark corridor.

Alex was stood close to where Jack was being interviewed, wondering what exactly was being said. Suddenly, an alarm began to blare and he knew that Nina had begun her escape attempt. Quickly making his way towards Medical, he could only hope that if she was caught, that Jack wouldn't take his chance to kill her.

"Nina?" Alex called out as he entered Medical carefully, only to find a bloodbath his sister had left behind. Soon joined by Jack and Tony, he noticed one of the medical staff cowering in the corner of the room. She pointed in the direction that Nina had fled.

Kim had been looking around for Nina herself, and as she saw the guard dead on the floor she wondered just how close she was. Picking his gun up, she cocked it and told herself that she might have to use it.

Nina herself was in a room that she knew all too well, the room where she had planned her escape and where she had killed Teri Bauer. Busily pulling at wires in an attempt to override the lockdown, she didn't notice Kim enter the room at first.

"Nina," Kim spoke firmly, her gun pointed straight at Nina, who turned slowly to face her before smirking. Nina contemplated whether or not to shoot Kim, although she wondered if she could really be that cruel to Jack. Of course, even more important to her, she knew that if she killed Kim, Jack would stop at nothing to make her suffer.

"You won't shoot me, Kim," Nina spoke, almost demanding that Kim walk away.

"Dammit, Nina!" Kim shouted, although her voice sounded more nervous than she would have liked. Nina smiled and began to slowly raise her own gun. Kim tried to remain calm and to build up the courage to shoot, when a shot came out of nowhere and hit Nina in her right shoulder, sending her crashing to the floor. Shocked, Kim looked at where the shot had come from and noticed her father.

Not too far away, Alex heard the shot and froze. He wondered, hoped, that it didn't signal the end of his sister's life and tried to figure out where the shooting had taken place. As he ran down the corridor, he could hear Jack talking and as he turned into the room where they were, he saw Jack fire three bullets into Nina as she led defenceless on the floor. A few moments of silence passed before Alex walked further into the room.

"Jack?" Alex spoke, catching his attention. Jack looked at him sadly, before walking over to him.

"I'm sorry, I had no other choice," he replied quietly, and Alex could feel the anger rising in him. The shot he fired into Jack's shoulder was quick and sudden and as Jack fell to the ground, he looked at him with a look of pure fury.

"Dammit, Jack! You just had to have your petty revenge, didn't you?" Alex yelled at him, pointing his gun at Jack's chest, willing to take his life. Jack looked up at him with shock.

"Alex, please calm down! This doesn't have to get any worse, OK?" Jack pleaded with him, and he was relieved to see a sudden calmness on Alex's face.

"I'm afraid I'm doing this whether you like it or not. Not like it matters, I've done this once before tonight anyway," Alex spoke and for a moment, Jack was confused by what he meant. He was horrified when he realised.

"You killed Chloe, you son of a bitch!" Jack shouted, but Alex simply smirked.

"Yes, and thanks to you, she died unnecessarily," Alex replied, and he was about to finish Jack off before he heard guns cocking behind him. Freezing, he cursed inwardly.

"Drop the gun, Alex!" Tony demanded. As Alex complied, he looked at Jack hatefully until he was led away from the scene in handcuffs. Chase crouched down near Jack, a look of shock on his face.

"You OK, Jack?" He asked, not sure what to make of what had just happened.

"I will be," Jack whispered.

As he escorted Alex down the corridor and towards the holding rooms, Tony stared straight ahead and tried not to think of the night when Nina was arrested. That night, he had seen her bitter, cruel eyes looking over the roof of her crashed car, and that night an innocent had been killed in cold blood. Even if he could understand Alex's anger towards Jack, he couldn't understand why he had to kill Chloe.

Jack was in pain, but he knew that he had to do everything he could to stop the virus threat and as Chase helped him to his feet, he tried his best not to show any signs of discomfort. The bullet was still lodged in him, but he felt that it would be enough for it to be bandaged until a doctor could look at it properly. Wiping sweat from his face, he caught sight of Nina's greying body before quickly turning around and walking out of the room with determination. He was going to stop this threat before he could worry about the events that had just unfolded.

Chase had been shocked to see Alex and Jack when he and Tony had reached the room, yet he could understand why Alex was so willing to kill Jack. Although he knew only bad things about Nina Myers, he was aware that the two were siblings and a bond still remained regardless of what she had done. As he and Jack walked towards the bullpen he wondered how Kim was going to react. Her father had just killed her mother's murderer, her friend had come close to killing her father and that friend had also confessed to the murder of Chloe O'Brian.

As they entered the holding room, Tony simply pointed to a chair before leaving Alex alone in the room. Sitting down, with his hands cuffed behind him, Alex wondered what was to come next. He knew that the murder of a federal agent would mean that he potentially faced the death penalty, but what was worse was that he knew what he had truly done - he had proved them all right. He knew that if anyone within CTU knew of Nina then they knew of him, and many would not be surprised to see that he had too had turned out to be a murderer. Now that Nina was dead and since he had been trying to stop her from being brought to CTU, he could only hope that they would not also accuse him of being a terrorist or traitor, working with his sister, which couldn't have been further from the truth. Sighing, he closed his eyes and wished that he was almost anywhere else.

Walking back to the bullpen, Tony tried to forget about Alex. He was the Director of CTU with a dangerous threat that needed to be stopped and, as he reached Michelle, he wrapped his arm around her lovingly, wanting to be close to her. Sighing quietly, he looked at the screen Michelle was reading from and forgot about Alex.

As Jack entered the bullpen, a concerned Kim rushed up to him and her worries only increased as she noticed his wound, but the bigger shock for her came when she was told about what Alex had done. Jack noticed the look of betrayal in her eyes as he spoke, and that angered him more than what Alex had just done to him because Alex had known how Kim had been hurt by treachery before. Assuring her that he was OK, he walked towards Tony and Michelle, more determined than ever to stop the virus.

Chase was still shocked as he reached his workstation and, as he slumped into his chair, he stared blankly at the screen of his computer. Just a short while ago, he had only seen a massive difference between Alex and Nina Myers, and now he only saw similarities. The whole night had been crazier than anything he had ever experienced before.