A/N: I couldn't resist throwing in a surprise appearance from one of my favorite characters. This chapter is kind of a filler chapter, but I knew that I had to work him in somehow.

"You ready for this?" Kelly asked as he and Gabby walked up the pad to 51. It was two weeks after Christmas and was Gabby's first shift back.

"Yes," Gabby replied happily.

"Gabby!" Brett greeted her with a hug, squealing. "I'm so excited!"

Gabby laughed at the younger woman's enthusiasm. "It's going to be fun being partners again," she agreed.

The three of them were heading to the locker room when the tones sounded. Ambulance 61. Heart attack. 1601 South Hallstead.

Kelly smiled as Gabby shoved her bag at him and took off for the ambulance, Brett not far behind. He picked up Brett's bag from where she'd dropped it on the floor and continued on to the locker room.

"Hey, Severide," Mouch greeted him, entering the locker room shortly after him. He looked around, his face dropping when he didn't see what he was looking for. "Where's Dawson? Isn't this her first shift back?"

Kelly held up the two extra duffle bags he was carrying. "Ambo got a call as soon as we got here," he informed the older firefighter.

"Oh, okay," Mouch replied, looking relieved. "That's good; I was afraid she'd changed her mind about coming back."

Kelly chuckled, shaking his head. Gabby certainly had been missed. She definitely wouldn't have any problem fitting right back in.

By the time the paramedics returned to the station after several back to back calls, it was almost lunch time. "I hope Cruz isn't cooking today," Brett said as she backed into the engine bay. "I'm starving."

"Me, too," Gabby agreed. "And exhausted."

Brett flashed her a sympathetic smile. "It's been quite the first day back."

Gabby nodded in agreement. "Puerto Rico…it was crazy at first. It was like this, but non-stop. But the last couple of years it was a lot slower. I might have gotten a bit used to that," she laughed, opening the door and hopping out of the ambulance. She smiled as she saw Kelly and the rest of the squad guys sitting at the squad table. So much had changed since she'd left for Puerto Rico; it was nice to see that at least something was the same.

"Well, whatever is cooking smells amazing," Brett remarked as she and Gabby headed towards the common room. "So I think we're safe from Cruz's cooking today."

Kelly watched Gabby as she walked past the squad table and into the common room. She was smiling and laughing, so their calls must have gone well. He'd hoped she'd have an easy first shift, but that obviously wasn't going to be the case, so at least it seemed as though their calls hadn't been too bad.

"There she is!" Herrmann called as the paramedics entered the common room. "Welcome back, Dawson!"

Gabby smiled. "Thanks, Herrmann. It's good to be back." She glanced towards the kitchen. "Who's cooking? It smells amazing."

Herrmann grinned. "A visitor stopped by and volunteered to cook for us," he told her. "They're talking to Boden right now."

Brett and Gabby exchanged puzzled glances. It wasn't uncommon for victims they rescued to drop by with donuts or some other baked good, but for someone to cook for them? It had never happened in all of the years Gabby had been with the CFD.

"A visitor?" questioned Gabby.

Mouch shrugged. "It was either that or Cruz."

"Hey, I heard that," Cruz complained as he walked in, followed by the rest of squad.

"It's said in love, Cruz," Gabby told him affectionately.

"Yeah, yeah," Cruz replied, rolling his eyes. "So, when's this food going to be ready? I'm starving."

"Now," said a familiar voice from behind Gabby.

"It can't be," muttered Brett, glancing at Gabby.

When the two women turned around, Brett squealed and launched herself at the visitor. "Mills!"

"Hey, Brett," Mills replied, laughing as he wrapped his arms around the blonde.

Gabby stood smiling as she waited for Brett to finally release Mills. "Hey, Peter Mills," she greeted him when Brett finally stepped back. "It's good to see you!"

"Hey, Gabby," Mills greeted her, giving her a hug.

"So, about that food…" Capp said from behind them, causing them both to laugh and roll their eyes.

"Okay, okay," Mills replied, going to the oven and pulling out two large pans of lasagna. "Here you go."

Gabby felt Kelly come up behind her and slip his arms around her waist, kissing the back of her head. "Hi," he murmured.

"Hi," Gabby replied, smiling. "Did you know about this?" she asked, glancing up at him.

Kelly shook his head. "I had no idea. He just showed up here a couple of hours ago. He said he was in town visiting family."

"Hey, Peter Mills," she called. "How long are you in town?"

Mills looked over at Gabby, a look of surprise crossing his face when he saw her with Kelly. "A week," he replied. "I got in yesterday."

"You're coming to Molly's tomorrow night, right?" Gabby asked, although it was more of a demand than a question.

"It depends," he replied, a serious look on his face. "Is my favorite bartender going to be working?" his face broke into a mischievous grin.

Gabby laughed at Kelly's quiet "Hmph."

"Stop being jealous," she whispered before responding to Mills. "Of course." She had started working at Molly's again a couple of weeks before Christmas.

"Then I'll be there," Mills promised. "Besides, how else am I supposed to catch up on all of the firehouse gossip?" He looked pointedly at her and Kelly. "It seems like I missed a lot while I was in North Carolina.

"Here you go," Gabby said, sliding two beers across the counter to Kelly and Mills.

"Thanks, Gabby," Mills told her. As she walked away to serve another customer, he turned to Kelly. "So, you and Gabby, huh? I didn't see that one coming."

Kelly laughed. "Neither did I," he admitted. "It's a long story. Let's just say we were both drunk and things happened."

Mills raised his eyebrows but didn't push. "She seems happy," he replied. "There's a sparkle in her eyes that I never saw there when she was with Casey. I'm happy for you two."

"Thanks, man," Kelly replied. "What about you? Anyone special in your life?"

Mills shook his head. "Nah. Running a restaurant doesn't get nearly as many women interested in you as being a firefighter does," he joked.

"Have you ever thought about going back to it? Firefighting, that is," Kelly clarified.

Mills took a drink of his beer before replying. "All the time," he admitted. "But you know how it is. The restaurant keeps me busy, and Mom and Elise need me."

"I saw you at the firehouse yesterday. The way you looked when we got called out. You miss it," Kelly insisted.

"I do," Mills admitted. "But Mom and Elise…I can't just leave them. You know how it was; how worried my mom got. I can't do that to her again."

Kelly nodded. "Well, if you ever change your mind, I know we'd all love to have you back."

"Thanks, Severide," Mills replied.

"Are you going to hog him all night, Severide?" Brett complained, coming over and taking a seat on the other side of Mills.

Kelly rolled his eyes, but turned his attention back to Gabby, letting the two former partners have a chance to catch up. God, she was gorgeous. She was down at the other end of the bar, laughing at something Cruz or Capp had said, refilling their drinks. She glanced over her shoulder, feeling his eyes on her, and smiled at him before turning her attention back to Cruz and Capp.

It had been amazing to have her back at the firehouse with him yesterday. It had been a busy shift, so they hadn't had as much time together as Kelly had hoped, but still. Just knowing she was there made it better.

"You've got it bad, Severide," Mills joked, pulling Kelly's attention away from Gabby and back to his friend.

"I keep trying to convince him he needs to ask her to marry him," Brett stated.

Kelly rolled his eyes, shaking his head. "I'm just waiting on you and Casey to get your act together first," he teased the blonde paramedic. "I'd hate to beat you guys to the altar."

Mills' eyes grew wide. "Wait, Casey? As in Lieutenant Casey?"

"The one and only," Cruz replied from behind Mills. He took a seat next to his lieutenant. "Only it's Captain Casey now. He and Brett got together after he and Dawson got divorced."

"Wait; Casey and Gabby were married?" Mills exclaimed.

The three current members of Firehouse 51 burst into laughter, leaving poor Mills even more confused.

"What's so funny?" Gabby asked, coming over and leaning onto the counter in front of them.

Mills shrugged. "They were just filling me in on some things that happened after I left. Like you and Casey getting married, and divorced, and then he and Brett getting together."

Gabby smirked. "You've missed a lot, Mills."

"Yeah, I guess I did," replied Mills, still trying to wrap his mind around everything.

Gabby laughed. "That's how I felt when I came back from Puerto Rico. So much had changed around here since I'd left."

"You were in Puerto Rico?" Mills asked, looking confused. "I mean, Mouch said something about it being your first shift back when I was at the firehouse, but I had no idea you'd been in Puerto Rico."

"I went there to do some relief work," Gabby explained. "At first it was just going to be temporary; a chance for Matt and me to take a break and think about some things. But then it turned into something more permanent. I just got back about five months ago."

"What made you decide to come back?" Mills asked.

Gabby looked at Kelly and smiled. "Kelly did, in a way. It's a long, complicated story, but the short version is Kelly and I ran into each other when I was in New York for a fundraiser, we both got extremely drunk and slept together, and then some things happened that meant I had to leave Puerto Rico. So, I came back to Chicago," she informed Mills.

Mills chuckled. "I never pictured you two together," he told the couple, "but you both seem happy." He turned to Kelly. "Just know that if you break her heart, I will come back here and make you pay," he warned him, only half joking.

Kelly grinned. "Don't worry; I have no intentions of breaking her heart. I'm afraid she's stuck with me."

Gabby leaned over the bar and gave Kelly a kiss, causing Cruz, Brett, and Herrmann, who had just walked over and joined the group, to groan.

"Come on; what did I tell you about PDA at the bar?" Herrmann griped, but the older man was smiling.

"Sorry, Herrmann," Gabby replied, although from the look on her face it was very obvious that she wasn't the least bit sorry.

"Kids these days," Herrmann retorted, shaking his head.