This crossover takes place toward the end of Fire's season 5, P.D.'s season 4, and Med's season 2. Dawson and Casey are married but at a crossroads regarding the future of their family. Halstead has severed all ties with his ex-wife and has been rebuilding his relationship with Lindsay. Rhodes and Reese are each committed to other relationships, but fate works hard to throw these prior commitments into the fire...

"Are we ever going to be a family? I just keep thinking about it since Louie left."

"We are a family."

Matt's words had echoed endlessly on a loop inside Gabby's brain ever since he had uttered them a month ago.

She remembered Matt kissing her as soon as the words had escaped his lips, and the way their evening had continued without further discussion of the subject.

They had dined warmly, watched the Blackhawks zealously, and embraced sleeplessly into the wee hours of the next morning. All the while seeds of uncertainty took root in Gabby's mind.

Is this enough? She had asked herself endlessly. Are we locked on this childless course and bound for eternity?

For a solid week Gabby had perused Matt's answer to the question that remained at the forefront of her mind.

"We are a family."

Was he simply being supportive? Was he having second thoughts about having children around? What had happened to the Matt who had wanted kids for his entire adult life?

Perhaps most darkly, Gabby sometimes wondered Is it me? Was it the miscarriage?

These concerns had made her insides shrivel, yet Gabby had held her tongue and proceeded as normal, as though Matt's answer had left her satisfied. Internally, she felt incomplete-emptied by Louie's departure- and suspected that there was only one way to fill the void.

It had taken a particular call about a week after Gabby had first asked the question for discussion of the subject to be revived between she and her husband.

By sheer coincidence, Matt had ended up helping Gabby to deliver a baby in the half-collapsed basement of a house. The walls had threatened to implode around them through the duration of the delivery, and Matt and Gabby had found themselves alone, afraid that shifting any wreckage to admit assistance might bury both they and the mother-to-be. Miraculously, both mother and infant had come through the birthing, and careful relocation of debris after the fact had narrowly enabled escape.

Gabby had watched Matt present the anxious husband, who had been stuck on ground level for the duration of the delivery, with his newborn son. She had watched Matt's eyes, alight with adrenaline, and perhaps envy, as he observed the infant in the man's arms.

That night Gabby had summoned the courage to revisit the subject of family with Matt.

"That was a hell of a rescue today." She had muttered as they sat down with a late-night order of Chinese food after shift.

Matt smiled, his blue eyes boring brightly into Gabby's. "It sure was." he admitted readily, dishing noodles onto his plate. "It reminded me of a highway delivery you walked me through several years ago."

Gabby cracked a gentle smile, her eyes darting up to meet Matt's in calm reminiscence as, simultaneously, her heart beat wildly inside her chest. "That one was amazing too. The ones with newborns and happy endings always are." she replied breathlessly.

"Is it the babies or the grateful parents-" Matt mused, sipping his drink "that make them amazing?"

"Definitely the babies." Gabby admitted, "Though the parents are good too." She added quickly.

She let her eyes fall on him once more and cleared her throat in anticipation, her hands pressing nervously into her lap.

Both Gabby and Matt opened their mouths to speak at the same instant, their forks hitting their plates and their gazes locked.

"You go first." Matt insisted with a chuckle and a smile.

Gabby exhaled sharply, "Matt, I know what you said about us being a family, and we are- we always will be- but…" she trailed off, eyes averted, fearful of what Matt's expression might be. "...I feel like a part of us is missing, since Louie left. Now I know what it's like to...have a child...I want it for us again, if you do too, that is." she finished with a stammer. "I want our family to be more." she confessed quietly. "I want to have a baby."

Gabby raised her eyes very slowly, out of fear of Matt's response. Her heart skipped a beat as she saw that he was smiling. After a lengthy pause, he spoke.

"You took the words right out of my mouth."

Gabby burst into a jubilant smile and leapt from her seat. She embraced Matt tableside and felt her fears ebb away. A thin stream of joyous tears made their way down her cheek as she held Matt tightly.

"I never wanted to push things, after what happened last time." He whispered into Gabby's shoulder, his voice choked. "But nothing makes me happier than to hear you say those words." he promised, pulling away from Gabby and taking her face gently in his hands. "I'll be with you every step of the way. Always." he breathed, planting a kiss on her forehead.

With those words their new path was set.

Matt and Gabby made an agreement that if nothing occurred "naturally" within a couple months, they would seek professional advice on the matter of conception. Gabby spoke enthusiastically of apps, supplements, diets, tricks, and home remedies which might speed up the process, though as it turned out, intervention was hardly necessary.

Now, a mere month after Matt had first reassured her that they were, indeed, already a family, Gabby found herself wondering if they were to become three sooner than expected.

It started when she fell asleep in the passenger seat of Ambulance 61 as Brett drove back from a call on Wabash. Her partner had shaken her awake as they pulled into the firehouse and joked about her incompetence; though mentally Gabby noted with a hopeful jolt that she was exhausted despite reasonable amounts of sleep the previous few nights.

The next few mornings brought nausea, which she did her best to hide from Casey, lest he become prematurely suspicious.

Finally, Gabby realized she was a week late, a realization after which she conceded and decided to do the test.

The particular morning she chose was a rare day off that she had booked long ago for the purpose of helping Antonio with an event. Gabby contentedly remained in bed, intending to sleep in as Matt left for the firehouse. He kissed her goodbye and promised he would be seeing her that evening.

As soon as she heard the door to the apartment click shut, Gabby slid out of bed and shut herself in the bathroom.

Moments later, her hand flew to her mouth and she emitted a muffled shriek as the two lines on the test appeared. Her heart thudded heavily in her chest and she wanted to bawl tears of joy. Though that, she suspected, had more to do with hormones.

A second chance. Gabby thought giddily. We have a second chance at a family.

She strutted joyfully around the apartment, feeling lighter than air as she got ready to go and meet her brother.

She was tempted to call Matt immediately, needing to share some of her excitement, but forced herself to wait.

The moment should be perfect when I tell him. Gabby instructed herself strictly. In fact, no one should know until the moment is right.

So her secret would remain locked up, for now.

Gabby realized suddenly that in her enthusiasm she had lost track of time. She glanced at the clock and felt her heart stop as she registered 9:31.

I was supposed to meet Antonio at the restaurant at 9:00! She remembered with horror.

"Shit." She cursed, grabbing her purse and her jacket in a flurry. "Shit, shit, shit, shit, shit." She mumbled to herself as she flew out the door, nearly forgetting to lock up the apartment behind her.

Months ago Gabby had agreed to help Antonio with a very important catering job for his wife's- perhaps his ex-wife, now- restaurant. A very prominent Chicago philanthropic society was hosting a fundraising dinner on a luxury riverboat, which was set to sail the Chicago River tonight for several hours.

Antonio's restaurant was short-staffed for the event, so Gabby had reluctantly promised to lend a hand, telling herself she would get to spend a night on a fancy boat and could enjoy a "day off" in which she would cook instead of saving lives…

Now she had some reservations, particularly not wanting to deal with the inevitable tension that would brew between Antonio and his ex-wife when forced to work together for most of the day.

With a sigh Gabby reminded herself, you're doing it for your brother, and so you can spend an evening on a Riverboat on the Chicago River.

Besides, nothing can ruin this day. She decided jubilantly, smiling and placing a hand over her belly as she pulled up in front of the restaurant.