Hello everyone, and welcome to my new story. It is a sequel to "Pain", and even though I'd be happy if you read it, I am sure you would easily follow this one even if you don't. It's funny, because I had this idea long before the last episode of Chicago Fire aired, and I'm so looking forward to seeing what happens in our favorite show next. I tend to update once a week.

Warning: The story contains spoilers for season 3, 2 and 1

Disclaimer: I do not own any of the characters or the plot of Chicago Fire and Chicago PD. I do not own the lyrics of the songs used. This story is intended for fun only and I am not making any money with it!

Chapter 1

A dark figure walked through the back exit of an old warehouse, making sure to avoid every video camera around. He had planned it well – he knew every single detail of the building, knew where the guards were, where they liked sitting during shifts, where the manager's offices were. He made his way to a relatively big room on the first floor and looked around in satisfaction. It was all going so well. He put a small radio close to the door, with the "turn on" timer counting down the minutes until it was time…Very carefully, he positioned two small propane tanks in the corner of the room, then took out a metal coil, sitting on an oxidizer…It was payback time.

Xxx

"Hey, look who's back!" Herrmann exclaimed when Kelly Severide walked into the locker room ten minutes before shift. It was his first shift after four weeks of attending the meetings of Kara's support group…four weeks of hell, preceded by months of even worse hell, if it was any possible. Squad Lt. had gone through the impossible – losing Leslie Shay two years after his childhood friend Andy Darden had died. After his complete breakdown four weeks earlier, he had put a lot of effort into building his life again, but it was just hard.

"It's good to see you back, Lieutenant." Cruz added, patting Severide's shoulder before heading away.

"Not that we didn't like your relief lieutenant." Otis grinned and went after Cruz.

"Yea." Kelly muttered in response. He spent the next few minutes changing into his uniform before slamming the door of his locker shut and heading to Boden's office to have a word with him. Frankly said, Squad Lt. wasn't feeling ready to be back, but it was all part of the healing process, or so they said. Luckily, the alarm sounded, calling Truck 81, Squad 3 and Ambulance 61 to a structure fire.

Severide took a deep breath and ran towards Squad, not responding to any of the remarks his buddies made. Everyone was glad to finally see him back, but they had their own way of showing it.

"Nice welcome back call." Capp took his eyes off the fire in front of him and shook his head in disbelief, just before Tony pulled over close to the burning warehouse. Its five storeys were already consumed by flames, but by the look on Boden's face, there were people inside. Kelly jumped off his seat and joined Chief and Casey, who had arrived a few seconds earlier.

"There are at least four people inside!" Boden informed them. "Two guards on the ground floor, the manager and his son probably on the third or fourth!"

"Copy that, Chief!" Kelly didn't need any more instructions. He put on his mask and helmet and yelled orders to his men before running into the building.

"Cruz, Herrmann, vent the roof! Otis, take Dawson and lock up the elevators." Casey didn't want the father and son panicking and taking the elevators. "Mouch, you with me. Need to find the guards fast!"

Boden watched through greeted teeth as everyone spun into action. He had a bad feeling and the cloud of black smoke that came out one of the windows just after the last of his men disappeared inside the building didn't help. He could hear through the radio Severide yelling for anyone there to call out, Casey doing the same on the ground floor.

"I…flo…check." Chief recognized Otis' voice, but he couldn't make any sense of the words.

"Otis…s…again." Matt ordered.

Boden's eyes locked with Mills', both of them reliving the moments before the building that had taken the life of one of their own had exploded. They felt relieved when Mouch and Casey emerged, supporting the two guards. Mills and Brett guided them to the ambulance, while Truck Lt. was preparing to go back inside.

"Lost contact with Otis and Dawson!" Matt yelled loud enough for Chief to hear him through the mask. He had barely made two steps towards the entrance when an explosion on the first floor knocked down all the windows. Not wasting a second, Casey stormed inside, hoping that everyone was safe and sound. He ran into Newhouse and Capp, who had the father and son.

"Severide?"

"First floor. Dawson said that Otis is down!" Capp replied, not having time to reveal more details. Matt took the stairs two at a time, joining Severide in the search of their fallen brother close the place where the explosion had taken place. Kelly had pushed Gabby aside, not wanting to risk her life, too.

"Otis, call out!" Squad Lieutenant yelled, moving through zero visibility towards the sound of Brian's pass device.

"Otis!" Casey tried again, following Kelly, until they reached their brother. The explosion had dislocated his helmet, but his mask looked intact. Both men felt relieved when they heard Otis groan and move his hand in an attempt to push himself upright.

"Come on, let's get the hell out of here!" Kelly ordered. The two lieutenants helped Otis all the way to Ambo Sixty-one, where a pair of paramedics were expecting them.

"I thought I heard someone calling for help…there was nobody in there." Brian tried to explain before Ambo took off on its way to the hospital. According to Chao, one of the paramedics, Otis was going to be okay, but they were taking him there just in case…

Xxx

Next morning Kelly was first to leave the firehouse after shift was over, thankful that Otis had been sent home after the hospital visit and would return to full duty starting next shift. He had hidden it well, but almost losing another member of Fifty-one had brought back his fear that everyone he cared about was going to leave him. He knew he was on the verge of losing it, so a few seconds after shift ended, Kelly sneaked out through the back exit, driving away. Half an hour later, he pulled over in front of the familiar house, where Kara held the meetings of the support group for firefighters who had lost close family and friends. It had been four weeks since Matt and Lindsay had talked him into coming for the very first time, and he hadn't missed a single meeting since. Kelly walked inside slowly, joining the group, everyone being there already.

"Kelly, you have something to share?" Kara looked at him, having noticed his concerned expression. She hadn't admitted it loudly, but he was one of the hardest patients she had ever had.

Severide looked away for a moment, knowing that bottling up his emotions wouldn't do him any good. He had promised Shay that he would fight his demons and he had to keep the promise, no matter how hard it was.

"I...we almost lost another one yesterday. This was my first shift back, and Otis almost died!"

"What happened?" The firefighter left of him asked, having lost men himself.

"I don't know…there was something blocking our communications, the next thing I heard was an explosion somewhere below me. Made my way downstairs and heard Dawson yell that Otis had gone into the room where the explosion happened…it just reminded me of the day Shay died, I guess."

"This is normal. You just shouldn't let it get to you."

"Yeah, 'cuz you know what it's like to lose people inside burning buildings!" Kelly barked icily, starting to regret his words the moment he said them.

"No, I don't. But I know what you're thinking and I'm telling you that what happened on shift is not your fault. It's your job to run inside burning buildings and things like this happen way too often."

"And they all happen when I'm around, damn it!"

"C'mon man, every one of us has lost people, am I right?" Mike, a Squad lieutenant, exclaimed, and eleven "yes" were heard.

"Plus, your man is okay, right? I bet you were the one to get him out."

"Me and Casey."

"See? You saved his life, man."

"Yeah…" Kelly murmured, not too convinced, but glad that there were people who knew exactly how he felt.

Xxx

***One week later***

"Close the door, Casey." Boden ordered with deep sadness in his voice. He had been sitting in his office with a man from Arson Investigations for the past one hour, and by the looks on their faces, the topic wasn't any good.

"What's going on, Chief?" Matt sat on the only free chair, waiting for an explanation.

"You remember the first structure fire after Severide came back?"

"I do…almost lost Otis." Casey said as a reminder, even though he was sure that Chief remembered that they had been close to losing another one.

"We found this." The Arson Investigation man pulled out a metal coil, sitting on something way too familiar to Matt and Boden. "It's been used to start the fire."

Casey looked at Chief with a horrified expression, having the feeling that there was more to the story.

"Another team has found the same coil near the propane tanks that exploded when we…lost Shay" Chief barely made himself say these words. "Seventeen fifty-one written under the oxidizer."

"It wasn't until we opened this case that we saw the link." The AI guy tried to defend his colleagues.

"You mean the link to Hadley?" Casey clenched his fists tight, his anger about to explode.

"We cannot tie him to these fires. Hadley's in prison after spending six months in a burn centre."

"Does Severide know?" Matt ignored the Arson guy for a moment, focusing his attention on his friend. What he had been just told had the potential to push Kelly back to square one, or worse - completely destroy him.

"No…not yet." Boden sighed, wishing for the nightmare to be finally over. "And I prefer it to stay this way for now, at least until we have solid evidence."

"Yea." Casey nodded in agreement. He was scared - scared what Kelly might do, scared how Dawson was going to react, scared that it could hit the house badly. Losing someone was tough, but finding out that someone you had worked with for years was responsible was way beyond this. Truck Lt. exchanged a look with Chief and then fixed his eyes on the AI guy. "You talked to Hadley yet?"

"I did. He found it hilarious but said nothing! And the truth is that he has a solid alibi and we have no evidence, except for this coil, which doesn't prove much."

"Doesn't prove much?" Matt stood up, kicking his chair away, finding it hard to keep his temper in check anymore. "Severide's badge number is written underneath!"

"It only means that these fires might be connected to him! Look, I know that it's personal for all of you, but you need to be patient and let me do my job. Just be extra careful handling similar fires and I'll tell you if we find anything new.

"You better." Casey's words sounded more like e threat and Boden couldn't blame him for this, as he was feeling the same way. He watched in silence as Truck Lt. turned around and stormed out, wondering if they would be able to hide the information from Kelly.

Xxx

When Casey got home after shift, he was happy to see that Kelly wasn't home yet and Gabby had gone to Molly's with Herrmann to sort out some bills. Matt had been avoiding Squad Lt. all shift long, fearing that Severide could somehow guess by the expression on his face what was going on. Truck Lt. knew that they couldn't afford it – for Kelly's and everyone else's sake. Severide was doing his best to hide it, but he was still getting upset every time he or anyone else mentioned Shay or Darden, every time he saw a blond woman or they had a call with casualties. Boden had asked Capp to keep an eye on Squad Lt. during and after calls, just to make sure he was okay. It didn't mean that Chief didn't trust Kelly, no, the thing was that Severide didn't trust himself. So what if he found out that an ex-member of his own Squad was responsible for the death of Shay? What if he found out that his best friend had died, because an insane ex-firefighter was targeting him, when he had worked so hard to convince himself that it wasn't his fault? What if the attacks on Fifty-one weren't over? How would it affect everyone else?

Matt grabbed a mug of coffee and crashed on the couch, trying to answer these questions, without any luck. He was actually relieved when there was a knock on the door. He pushed himself upright, letting Lindsay in.

"Hey, what's up? Kelly okay?" She looked at him, worried. She had got a weird call from Matt, asking her to stop by his place as soon as possible, not explaining the reason.

"Yea, he's finishing up some paperwork that has piled up."

"Then what's going on?"

Matt took a deep breath, not knowing what to begin with. "You should probably sit." He waited until she made herself comfortable on the coach and brought another streaming coffee for her. During the next fifteen minutes he told her everything about the conversation with the AI guy and Boden he had had, feeling relieved that he had finally shared it with someone. Casey and Lindsay had become really close friends during the nightmare with Kelly, so he knew she would understand him and the source of his worry.

"You know we can't hide it from Kelly forever." Lindsay sighed, thinking the same as Truck Lieutenant. "He was a main witness in Hadley's trial, was closest to where the fire that blew off the propane tanks started, and there is evidence that he was the target…It's a matter of time before AI talks to him."

"I know." Matt didn't bother to hide the frustration in his voice. "I don't like the guy leading the investigation." He added, giving a hint why he had called Erin.

"What's his name?"

"Alan Smith."

"I'll have a word with him. You can't imagine - " Erin stopped in the middle of her sentence, having heard the front door being open.

Kelly murmured a "hi" and walked into the kitchen, looking for the bread to make himself a sandwich. "Hate paperwork."

"Who doesn't?!" Lindsay smirked, finishing her coffee.

"What are you doing here anyway?"

"Came to get my purse." Erin was glad that she had really left her purse there after their last game night. The two had got very close in the past few weeks, closer than ever before, but they were still keeping things in the friend zone.

"Okay. I gotta go. See you at 7 at the cinema." Kelly grabbed the sandwich and his keys and headed toward the door.

"Where are you going?" Matt insisted on knowing, trying hard to sound normal.

"The boat yard."

Xxx

Six hours later, Kelly put the screwdriver he had been using to fix the motor of a boat in his car and got into the driver's seat, ready to go meet Lindsay at the cinema. He didn't want to admit it, but he was doing his best to keep himself occupied every second he wasn't at 51. So he was spending a lot of time at the boat yard, working for various clients, not because he needed the money, but because he feared that he might slip on a banana peel otherwise.

Kelly's phone buzzed in his pocket, but when he looked at the id of the caller, it didn't show anything. He narrowed his eyes, wondering who this could be. Another client maybe? Someone from the firehouse?

"Hello." He answered the call, his tone indicating that he was expecting for the caller to say their name. But what he heard next took him by surprise, scared him even.

"Kelly Severide." The gruff voice was clearly male, sounding like it was coming though one of these voice changer machines. There was no way Severide could guess who the caller was.

"Who the hell are you?"

"Someone who would make you wish you were never born."

"What the hell - "

"I guess your dear friend Casey and that police chick didn't tell you. And you thought you could trust them." The voice laughed sarcastically, clearly enjoying torturing the Squad Lt.

"Tell me what?"

"Tell you that it was your fault! I started the fire that took the life of your precious Leslie Shay. Ask them!..I lost everything I had because of you and your house 51. Now it's your turn…Ask them!" The line went dead, leaving Kelly to sit motionless in his car. So it was his fault after all. One wonderful person had died because of him. His best friend…the only one he could trust to was gone, because of him. And they all knew – Matt, Erin, Chief, everyone pretending to be his friend…He felt betrayed, again, felt as if he had nothing to live for, again. Kelly dropped the phone on the floor and covered his face with his hands, wishing for death to finally put an end to his misery.

Your heart is full of broken dreams

Just a fading memory

And everything's gone but the pain carries on

Lost in the rain again

When will it ever end?

The arms of relief seem so out of reach

(Red – "Not alone")

Xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Okay, if Hadley is in prison, who is our mysterious guy? Well, I am not gonna tell you yet, sorry! :)

For anyone wondering, 1751 is Kelly's badge number.

What do you think? Do you like it? Or maybe hate it? Please review, any comments would be appreciated!