Severide's eyes flutter open . He sits up and groans.

Really must stop going to Molly's

He comes off the bed and does a few stretches. Still half asleep, he goes to the sink and splashes water on his face .He brushes his teeth and spits. Again he splashes water. Although he still felt heavy-headed at least it's woken him up. He steps out of the bathroom and looks at his bed. This time he frowns.

That's not my bed.

He looks round at his surroundings and realizes this is not his room.

Did I pick a chic up in the bar

He rubs his head trying to remember. His mind was nothing but fog. The door is what caught his eye. He crouched down and admired the door that had to be around 5 inches. He glances at the white walls that had no pictures, no shelves. It reminded Severide of a cell.

The door slides open causing Severide to jump back. A woman walks through with a young man by her side.

"You had a good sleep Experiment 69?"

Severide looks at the woman studying her tiny face. He showed recognition.

"Dr Lewis" He looks at the man next to her with the familiar smirk "Dr Stevens."

He frowns as he looks at them than at himself. Then his memories come flooding back to him. He quickly gets to his feet looking at his hands, his feet. Comparing his size to the doctors, his got bigger. Bigger than what he was at Med.

"You were out cold for quite a well. Longer than we expected." Dr Lewis says.

Severide glares at her "You drugged me."

"With a strong dose yes." Dr Stevens says.

Severide looks at man with a flash of his anger in his eyes.

"You. You know her."

"Yes he does." Dr Lewis says "If you think about laying a hand on him I'll simply do this." She presses a button on her remote control.

"Oww"

Severide yells after receiving an electric shock.

"I'll keep turning the watts up if you misbehave. It will just become more painful."

" Why you doing this? " He asks.

"You are an experiment."

"An experiment? "

"One of my experiments." a new voice says.

A man walks in with the same matching lab coat as the other two. Severide knew in seconds who it was.

"Dr Marshall."

"Kelly Severide or should I say Experiment 69. "

Severide gets back on to his knees his fists clenched.

"You left me. You knocked me out."

" I had to. I needed your mask so I wouldn't breathe in the substance that you broke. The substance that has caused you to have this small problem. "

Severide's eyes widen. That red liquid Dr Marshall was holding that day is what has caused all this. Now thinking about it things have went weird after that day.

Why the hell did I not thought about that.

"Since you first checked into Med about the shrinking I had Dr Stevens here giving me updates. When you checked in again and Matthews requested the meds, Dr Lewis managed to swap the meds so Dr Stevens will take up the one that I created."

" I gave you the right amount. " Dr Stevens says with a wink.

"Why did you swap the meds."

"To ensure Med will stop trying to help you. We wanted them to face more problems that they will see it's too much for them to handle. I gave...well Dr Stevens gave you my other ingredient. It does the opposite to what the previous one did. Instead of shrinking you..."

"Grew."

" Yes. Dr Stevens changed the results to make doctors even more baffled so they would really have no choice but to give you up. "

"All this. Is all you."

" No. Kelly you done this to yourself. You should have not followed me that day. "

"I was doing my job."

"Look what doing your job has done to you. "

"I been through Hell cuz of you."

"Kelly I just said you did this to yourself. I'll say you have given me an advantage. I have looked at your recent results. Your real results. It seems your DNA has been altered and your cells have again changed. It's like you are a brand new species. "

"What?"

"It struck my interest. My original experiment didn't bother me anymore. This...this is so much better. As they say things do happen for a reason."

" I'm not an experiment. I just wanna be cured. "

"Kelly. Those days of being a fire fighter are over. You belong to me. You are my experiment. With the two substances inside you I can create you into something. Something that can be useful."

"No. No you are not taking my life away to be your guinea pig. It's not happening."

"What will father say when we visit him with a gun aimed to his face."

"You wouldn't dare. "

"Or maybe your mother or how about your friends at the fire house."

"Don't go near any of them. You hear me." The Lieutenant raises his hands as a sign to surrender "I'll do anything you want."

"Anything"

"Yes just leave my family alone."

Dr Marshall grins "Good. I just love it when people are willing to cooperate. Makes the work so much easier." He gets out his note pad and pen "Let's get started Experiment 69."

Both Casey and Dawson receive a message to the fire house it was urgent. When they arrived, the others are there sat down looking anxious by the news Boden is about to announce.

"Everything alright Chief?" Herrmann asks.

"I have bad news." The Chief says. He clears his throat "I'm afraid Kelly Severide will not be returning to the Firehouse 51. "

"What! Why? " Herrmann asks.

"As you are aware Severide hasn't been himself lately. His been diagnosed with a mysterious illness. His been transferred to the local facility hoping they might be able to find a cure. "

"What's the illness?" Mills asks.

"They kept that part confidential but his gonna be away for a long time. No one knows how long it's gonna take to get Severide back up on his feet again. "

"Can we visit him?" Cruz asks.

Boden sadly shakes his head causing everyone to frown.

"This is it? Severide we are never gonna see him again?" Herrmann says.

The room fell into an awkward silence it felt as though they received news that a close friend has passed away. Casey and Dawson exchange glances. They knew what happened to Severide. They knew what this mysterious illness was but they felt it wasn't a good time to share Severide's business.

"We have a new person to replace Severide as Lieutenant. People this is Dallas Patterson."

" I look forward to working with Squad. I do wish Severide a speedy recovery. " Patterson says with a smile.

Not one person felt enthusiastic about the new member to the team. Kelly Severide will and forever be the Squad leader of Firehouse 51. Someone else taking up the role didn't feel the same.

Kelly wouldn't like his job being taken away from him. Casey thought.

"We start fresh tomorrow. " The Chief says "Despite what's happened we keep going. You got that."

"Yes Chief"

"You are all dismissed."

The fire fighters and paramedics rose from their seats not one of them said a word. Casey remained in his seat worry rising up inside him.

Dawson holds his hand and gives him a comforting look.

"At least his getting the help he needs. " she says.

She stands up and leaves Casey on his own.

I hope you do make a speedy recovery Sev. Casey thought. "Things are gonna be weird without you around. I'm sure things are now gonna change now.

He looks at Patterson talking with the Chief outside

Definitely

Casey stands up and swings his bag over his shoulder.

Like Chief said we keep going. So that's what I'm gonna do.

He finds Dawson outside on her phone.

"Hey"

Dawson looks at him and smiles "Oh hi"

"Hey umm I was wondering you wanna go get a coffee. As friends?" Dawson hesitated. Casey nods "It's okay I get it. "

"Yes. Umm yes I will accept the coffee offer. Ain't got anything else better to do. I think after a day we had we definitely need a cup of Joe."

Casey smiles.

Maybe things are starting to look up. He thought.

"You drive. "

Casey chuckles "Of course"

They both get into the car and drive off.

6 Months Later

Casey and Dawson sat on the sofa with their arms round each other.

"Oh come on he clearly cheated." Dawson says throwing her popcorn at the television.

"The Ref disagrees." Casey says with a chuckle.

"No one disagrees with Gabby Dawson." She says throwing another popcorn at the television.

"Unless you want a death wish."

Dawson switches off the television and turns to her side looking into the Lieutenant's eyes.

"I was getting bored of the game anyway"

Casey grins and leans forward. He kisses her on the lips.

"Is this boring?"

Dawson giggles and wraps her arms round his neck.

"Never"

They lock lips and kiss each other passionately. They both fall back on the sofa and started to undress each other layer by layer. Dawson let out a groan as Casey kisses her stomach going upwards towards her lips. Again they lock lips and remain in that position for a while.

Outside their window. A dark shadow stood there looking in on the couple. The street lights gave off a bit of glow revealing the features of the stranger.

His skin is covered in bruises, scars and cuts from the neck down to his feet. He wore a black leather jacket with a top, trousers and boots all black. On the back of his wrist was a piece of writing tattooed to his skin saying.

Experiment 69

The man lowers his sleeve to hide the tattoo. He turns his back to the window almost speechless on how much has changed since he was last here.

The man began walking down the street. He suddenly spots a woman through the darkness dropping her late night shopping bags.

"Damm it" she cursed.

She was about to go down until a voice started her.

"Here"

The woman looks at the man holding her bags. She smiles.

"Thank you." She takes the bags. "Thank you so much umm..."

"Kelly Severide. " The man answers.

"Thank you Kelly." Despite the cuts in his face she found him handsome. "I'll say you are quite a dashing fellow."

" I'm a man of many sizes. " He says his eyes lowered sounding disgusted with himself.

"Oh umm..." She says not understanding what he meant "Have a good night." She quickly hurries off down the street.

The man sighs and continues walking. He enters the place where he used to work. Firehouse 51. He looks up at the building pain in his eyes.

Everything he worked to be his dream has all been taken away from him all because of this thing that was now inside him .On the outside he looked human but inside he was something entirely different.

He hated it.

"Excuse me may I help you?"

He looked. Outside the firehouse his former boss Chief Wallace Boden stood with a bag swung over his shoulder ready to leave after finishing his shift.

"Chief"

Boden narrows his eyebrows. Recognition showed on his face.

"Severide? "

"Hey Chief. Been a while."

Before Severide can move, Chief pulls him in for a hug.

"It's so good to see you. "

Severide smiles and hugs him back.

"You to Chief."

Boden steps back and eyes the ex Lieutenant up and down.

"Jesus what the hell happened to you?"

Severide waves it off "Nothing just all part of the curing process."

"Damm. You are disease free now? "

"Yes."

"Well that's great. Argh man you really don't know how much you were missed. We never stopped thinking about you. "

Severide chuckles "6 months and you were still thinking about me."

"You wouldn't believe. Hey you should stop by the firehouse tomorrow let people know Kelly Severide is back in town. "

"Uh...yeah."

" Obviously if you are still not... "

"No it's fine I'll come say hello to everyone." Boden smiles. "I better let you get home. Donna we'll be waiting for you."

" Have you got somewhere to go? "

"Yes. Chief don't worry about me."

" Okay then. Well I'll see you tomorrow. "

Severide smiles " Have a good evening Chief."

"You to. "

Severide watches as the Chief got into his car and drove off. The young man frowns and goes back on the path and started walking again.

He arrives at a local motel that was on the outskirts of Chicago. Severide checks his wallet. He curses when he finds no money. The young man shivered as the coldness starts to take over.

He couldn't sleep homeless. He needed a room. He walks up to one of the rooms. He closes his eyes and his face screws up and thinks hard.

Minute later, he opens his eyes and is faced with the gap of the door. He sadly looks up at the door that was now towering over him. He goes down and slides through the gap. Once in the room, he repeats what he did outside. Seconds later he was his normal height again.

The doc would be pleased He thought

Severide lies on the bed staring at the ceiling. He thought about seeing his friends again. Part of him wanted to go but his other half saw it as a waste of time.

I am not a firefighter anymore. I'm an experiment.

His eyes shift on to his tattoo.

I'm a weapon

Severide switches off the lamp and turns to his side hugging the pillow. He eventually falls asleep.

Later on that night, Severide's phone buzzed next to him. The screen lit up revealing a message from an unknown number. The message says in big capital letters.

NEXT TARGET

DALLAS PATTERSON

So that's the end. There might be a sequel or I might leave it like that. I will consider writing another CF fic. It was different for me. Thank you all for reading.