Serena Campbell stepped into the hospital reception, desperately trying to avoid Henrik Hanssen's unwavering stare that she had noticed as he stood waiting to pay for a cup of coffee. That was usually her first stop when she entered the hospital; the cafeteria - for a cup of freshly brewed cup of coffee, but today she was more intent on avoiding Hanssen. She rushed over to the lift, carefully keeping her focus on the tiled floor than anywhere else. It was a bit childish, but he had made his feelings quite clear; she was staying on AAU and under no circumstances was he going to allow her back on Kellar ward. She had tried reasoning with him, but he was unmoving on the subject and in some ways she felt it was his way of punishment for her non-referrals policy which had ended in the death of a man; albeit that his death was not entirely her fault, Hanssen had taken the brunt of it. Even the press had gotten involved. He was a bit stressed and she wasn't about to stress him out anymore, nor did she particularly want to speak to the man.

The door to the lift opened and she was about to step in when she noticed Michael Spence leaning against the lift door, smirking at her.

"Morning," he said.

"Morning," she replied, wondering if she should take the stairs instead. But the thought of having to traipse all the way up three floors was in no way appealing, so she bit her tongue and got into the lift, pressing the three button with the same amount of venom she felt towards the arrogant Mr Spence.

"No coffee today?" Michael pushed, clearly noticing the reason why she had skipped out on her usual routine of the day.

"I thought it would be a good idea to cut down on it," Serena attempted to smile.

"You chose a pretty bad day to quit," Michael chuckled as the doors opened, revealing a corridor full of patients on stretchers.

Serena followed Michael out, staring at the chaos in disbelief. "What the hell is this?"

"You didn't hear? Car accident," Michael answered. "I'll leave this lot to you," he motioned to the four stretchers in the corridor.

"Thanks," Serena mumbled before rushing through to the office she shared with Michael and dumping her things on a nearby chair. She was trying to avoid using Michael's desk, but seeing as it was clear that she was not moving from AAU, it would possibly be a good idea to get a desk for herself in here.

She grabbed a pair of gloves and headed back out to the corridor where she assessed which patient looked like they needed her attention first. An elderly man had gashed his head open and the bandages used by the paramedics were already soaked through. A young girl sat on another stretcher with what looked like a broken arm while her friend beside her seemed to be in shock and suffering from a few lacerations. On the last stretcher was a young man with blood all over his face and stomach. One of the nurses were trying to assist him when he turned on his side and coughed violently, spewing up dark red blood on the floor. Serena immediately rushed towards him.

"Nurse, do we have a name for this gentleman?"

"His name's Jeremy, Ms Campbell," Chantelle quickly answered. She had been sent down from Kellar to assist with the overspill in AAU.

"Jeremy, I'm doctor Campbell. Can you tell me what happened to you?"

The man mumbled something before squeezing his eyes shut in pain.

Serena reached down to touch his stomach and was met with a firm shove from him which took her by surprise. Chantelle glanced over at her in shock. "Are you okay?"

"I'm fine," Serena moved back towards the man. "Jeremy, I need to assess your injuries so that I can help you."

"No!" the man yelled.

"You could die," Serena said in her sternest of voices.

The man tried to get up from the stretcher but fell to the floor unconscious.

"Nurse Lane, give me a hand," Serena called to Chantelle who was immediately by her side and helping her lift the man onto the stretcher.

Serena lifted Jeremy's t-shirt to reveal five deep stab wounds. She took in a deep breath. "I thought this man was with the car accident?"

"That's what we were told," Chantelle looked up at her with wide eyes filled with concern.

Serena glanced over at the other patients. "We need to get him into surgery," she headed into AAU ward to inform Michael that he would have to tend to her other patients when something caught her eye. It was a patient that Sasha Levy was tending to; his eyes were fixated on the stretcher in the corridor. He looked angry as hell. She tore her eyes away from him to find Michael who was joking with a pretty young lady who had a bandage around her arm. Michael had always been a lady's man.

"Michael," Serena called. "I need to operate on a patient; you or Sasha will have to deal with the three others in the corridor before Hanssen gets wind of it."

"Too late," Michael sighed, glancing towards the lift area where the tall Swedish CEO was speaking to one of the female patients.

Serena quickly moved towards the corridor, just in time to hear Hanssen's final words to the girl. "Not to worry, we'll get you moved out of here in a minute," he said, immediately glancing at Serena.

"Miss Campbell, may I have a word?"

"Not now, I'm just about to head into surgery," Serena motioned to the unconscious man on the stretcher. "I'd be more than happy to catch up with you directly after."

Hanssen just nodded, knowing not to interfere with an emergency surgery.

Serena helped Chantelle wheel the man to the nearest theater ward where they would ascertain what needed to be done and how badly he had been stabbed.

The results were back and Jeremy had severed an artery in his abdomen and nicked several internal organs, most of which could be fixed including the bleeding in his left lung. They had cut him open and Serena was half way through with the procedure when she paused after hearing a loud bang outside the surgery theater. All five people in the room glanced around at each other.

"What the hell was that?" Serena asked, turning her attention back to her patient's insides.

"I'll go have a look," one of the male nurses said, quickly leaving the room.

There was another loud bang.

"That sounds like a gunshot," Serena mumbled, trying to get the bleed under control. "Suction, please," she barked at the female nurse who was distracted by the noise.

The door flew open and a tall, dark man stood in the door way, his eyes fixated on the patient. Serena immediately recognized him from the AAU.

"You're not allowed in here," the female nurse stepped towards him and was greeted by a gunshot to the chest. She toppled to the ground without a word, blood pouring from her chest cavity. Serena felt her heart skip a beat as she stood motionless with the scalpel in her hands. The nurse by her side had frozen as well.

"You don't touch him," the man said angrily. "You let him die, yeah?"

"I'm a doctor, I can't do that," Serena heard herself say.

The man raised his gun and shot a hole through the glass windows leading to the observation room next to Serena. "I'm not askin'," he shouted, holding onto his bandaged side.

Serena imaging they were both part of some kind of gang and that they had stabbed each other. "Please," Serena whispered.

The patient's heart rate started dropping.

"What the hell's going on in . . ." Johnny Maconie stood in the doorway, frozen as the gunman turned to him. Johnny stared at him in horror, holding his breath.

"You go tell 'em if they send anyone in here, I'll kill everyone, yeah?" The gunman shouted.

Johnny nodded and quickly back stepped out of the theater, glancing over at a nervous looking Serena.

"You need to let them take my colleague. She's hurt," Serena motioned to the nurse who was laying motionless on the floor.

"You don't get to make the orders," he stormed over to her, pressing the gun to her head.

The nurse whimpered by her side.

"Then at least let my colleague take her," Serena glanced at the terrified nurse.

The gunman seemed to be thinking this through.

"If you want this man to die, she can't help, can she?" Serena said in anger, trying to fight back the urge to shove him away and run.

"Fine," he nodded. "Fine, you take her," he pointed the weapon at the nurse and motioned for her to drag her colleague's lifeless body out of the theater. She quickly did as she was told. The adrenaline made her stronger than she looked and she quickly dragged the body through the doors without so much as a last look to Serena.

The alarms began to go off on Jeremy's life support machine.

"If he dies, you will be charged with his murder, do you understand that?"

The man looked down at Jeremy's face with contempt before spitting on it. "Who says I'm going to get caught?"

"Oh I don't think you'll be walking out of here. Things are about to get a lot worse for you."

"I'm not afraid of nothin'."

Serena's heart actually ached as Jeremy flat lined. She was so used to fighting to save patient's lives. It was a whole new concept to stand aside and wait for someone, who could be saved, to die while having their chest cavity wide open for the world to see.

"How exactly do you expect to be leaving here?" Serena asked. The look in the man's eyes made her resent asking the question.

"Put the knife down," the gunman turned to face her.

"Scalpel," Serena corrected numbly as she placed the instrument carefully on the tray beside her.

"You're gonna help me."

Serena glanced down at her dead patient and then back up to the man whose eyes were filled with rage and something else; it wasn't exactly fear. Was he high? Had they noticed it in the AAU?

"There's no way out that isn't heavily guarded," Serena said as he grabbed hold of her arm and pulled her to the other side of the stretcher.

"Who says we're going down?" He hissed into her ear, letting go of her arm so that she could get out of her theater gown and gloves.

Serena had a bad feeling about this. She pulled off her blood soaked gloves and dropped them on the floor, peeling her surgical gown off. The blood had gone through to her light green blouse. The thought seemed more of a violation than anything else.

The gunman grabbed her again and started heading out the door. He pushed it open and pulled her in front of him as two security men stood nearby.

The police would be here soon enough, Serena thought. It had all happened so quickly, most of the hospital were probably not even aware of what had happened. Serena glanced down at the floor, noticing the blood stains from where the nurse's body had been dragged into the lift and then the body of the male nurse that was crumpled into a heap near the doorway. Another senseless murder?

"Let's just calm down, mate," one of the security guards called.

"I'm not your mate!" The gunman screamed, pulling Serena towards the lift. "I will kill her if you get in my way! You hear me? She's dead if you get in my way!"

Serena was trying to reassure herself as the lift doors closed that he was not going to kill her, but she had to think of what might happen if he did. Eleanor would have to go live with her father and step mother in Canada. That wasn't the worst thing that could happen to the seventeen year old, but it was close.

The lift doors opened to reveal Hanssen and Michael, both looking worried.

"Miss Campbell?" Hanssen said, glancing at the blood on her blouse and the man behind her.

"You can take the next one, old man," the gunman growled.

"What the hell is going on?" Michael took a step towards them and the gunman raised his weapon from behind Serena's back.

"Stay away or she's dead!" He shouted.

Serena winced at the fury in his voice and glanced passed Hanssen and Michael to see the scared faces of Chrissie and Sasha Levy on AAU.

"Let's just calm down, Kai," Michael rose his hands in defense.

Kai? That was the name of the man who had decided to saunter in and kill people? Serena could have laughed if she wasn't so damn scared.

"Stay away!" Kai screamed as the lift doors closed. Serena hadn't even noticed what floor Kai had pressed. She glanced at the lit up button and felt her blood run cold. That was Kellar.

She started running through different tactics, but none of them seemed feasible. If only she were as cool headed as Hanssen; he'd know what to do in a situation like this. What would Hanssen do? She tried not to chuckle in bitterness.

"You move where I tell you to, yeah?" Kai's grip on her arm tightened as he pressed the gun deeper into her spine.

As the doors opened, Malik and Chantelle were joking about something and Ric Griffin was taking notes down while speaking to a patient. It seemed so much more tranquil.

Kai moved them both out of the lift and Serena noticed Chantelle's eyes dart towards them. Her smile quickly faded. "Miss Campbell?" She called.

Malik turned to look at them and his smile faded just as quickly. He took a step towards them, getting ready to find out what this guy was doing with a blood stained consultant, but Serena raised her hand to get him to stop. Her pleading eyes were enough to make him realize that it was imperative that he back away.

Ric had moved towards the reception desk and he could tell by Chantelle and Malik's rigid posture that something was wrong. He turned to see what they were looking at.

"Serena?"

"Ric," she managed to croak through the tightness of her throat.

"What's going on?"

"Just stay out of my way and she won't die, okay?" Kai hissed, dragging Serena down the corridor with him.

Ric started following them very slowly. "Let's just talk about this."

"Nothing to talk about."

"Surely there must be something we can do to get you to calm down."

"Ric," Serena said. "Just do what he says."

"Take me instead of her," Ric said, watching Kai's face for a reaction.

"You're not worth enough."

"Believe me, I'm worth a lot more."

"I don't think so," Kai continued dragging her down the corridor towards the stairs.

Elliot Hope and Jac Naylor were deep in discussion when they noticed what was going on. Elliot grabbed hold of Jac and pushed her behind him, sheltering her from a possible attack.

Kai dragged Serena passed them. Elliot's eyes locked onto Serena's for a few seconds. She was obviously terrified.

Kai pushed the door to the staircase open and pulled Serena in with him.

"Where are you going?" Serena asked.

"To take a look at the sky," Kai replied viciously as he forced her up the stairs.

Serena could hear Ric's voice behind them. It sounded as though he was calling the police. Serena continued up the stairs until they reached the roof door. Kai kicked it open and shoved her out into the open air.

The sun was hiding behind a thick dark cloud. The sound of a siren in the distance cut through what was usually a tranquil scene.

Serena couldn't help but wonder whether that siren was on its way to Holby City.

Kai rubbed his face as if trying to rid himself of what he'd done.

"What's the plan now?" Serena asked, once again, it was as though she was watching the scene unfold instead of actually living it.

Kai ignored her. He peered over the edge of the roof and then jumped back. "It's a long way down," he said.

Serena tried to fight the feeling of dread that was building up in her. Was this the way she would die? A bullet to the skull or by falling to her death? She couldn't imagine which would be worse. As a doctor, she knew the chances of being left brain damaged or paralyzed by both but she wasn't quite ready to never see her daughter's face again.

"Mr Harris," Hanssen's voice cut through the silence.

Kai once again grabbed Serena's arm, using her body as a type of shield.

"Mr Harris, it appears you're surrounded," Hanssen said in a dead pan tone. "If you would kindly release Ms Campbell, we can arrange to have a discussion in my office. I'm sure as you can understand, I won't be able to prevent your arrest, but I could put in a good word for you. My voice still carries in the health and legal system."

"I'm as good as dead."

"Release Ms Campbell and we can discuss it."

Kai moved towards the edge of the roof and for the first time, Serena could have sworn she saw a flicker of panic in Hanssen's eyes. She felt like sobbing. If he was worried, then there really was no hope.

She noticed two policemen step out onto the roof. At least one of them was armed.

"Put the weapon down, son," the officer called. "Let's not kill anyone else today."

Serena could feel the sense of panic as Kai stood up on the edge of the roof, holding onto her.

"Get away!" He shouted.

"Just calm down and release the hostage."

Hostage? She was a hostage? The thought seemed to surprise her for some reason. She'd always associated a hostage with one of those Hollywood movies with Bruce Willis and some Z list actress, trying to make it big. Never in a million years would she have imagined when she woke up that morning that she'd be viewed as a hostage.

Her mind cleared and she realized that she had been missing the dialogue between Kai and the policeman. Kai had gone quiet. He seemed to be taking deeper breaths.

"It's a long way down Ms C," he whispered in her ear. "But it's better than the alternative."

Suddenly she felt his body jerk as a gunshot rang out. She felt his grip on her loosen as his body began to fall backwards. She felt herself losing balance as her body started falling back with him.

Hanssen grabbed her back just as she began to panic, pulling her away from the edge and tightly against his chest. It felt strange to be embraced by a man who never showed any form of emotion, but at the same time, it was the kind of comfort she needed from going over the edge, so to speak.

The policemen had run to peer over the edge of the building. There was no doubt that Kai was dead.

"Why did they shoot?" Serena asked through the ringing in her ears.

"He was about to shoot you," Hanssen answered quietly.

Serena allowed him to guide her back inside where the cavalry had gathered. Chantelle lunged at her and held her in a deep embrace.

"I'm so glad you're okay, Ms Campbell," she said.

"Chantelle," Malik had to pry her arms off of Serena. "You're choking her."

"Are you okay?" Ric asked.

"I'm fine," she nodded. "How are the others?"

"Michael's in surgery with nurse McLean now. Unfortunately Dennis didn't make it."

"And neither did Jeremy," Serena said, trying to fight back tears. She couldn't allow them to see her weak.

"Jeremy?" Chrissie asked gently, rubbing Serena's arm comfortingly.

"My patient," Serena glanced at the policeman who was walking up to her.

"Doctor, may we take down your statement?"

"Can I get cleaned up first?"

"That should be okay," the officer nodded.

Serena headed straight to the restroom, worried that someone might follow her in. But they didn't. She locked herself into the stall and leaned against the wall. Her legs didn't feel strong enough to hold her. For the first time, she burst into an uncontrollable sob. She would have to get it all out here and now, because she couldn't go out there and let them see her upset. Or have her daughter seeing that she had been badly affected by what had happened. There was no way she was going to let them think that the little lady doctor was incapable of handling herself in tough situations and if that meant pretending to be fine, then so be it. She kept hearing Kai's whisper in her ear: It's a long way down, Ms C. But it's better than the alternative.