It was the moment fans have been waiting for all season – Crossover Week on NBC. And, it all came together Wednesday night in a heart-pounding, edge-of-your-seat, pulse-racing thriller event when three hit shows joined forces to catch a serial killer.

Cast members called it, “exciting.” Fans lined the streets of Chicago to watch the plot unfold. It was, indeed, remarkable.

Actors from Chicago Fire, Chicago PD and Law & Order SVU teamed up on-screen to work a case, involving all three agencies.

It started with arson on Chicago Fire, which then turned into a sinister, deviant investigation involving Chicago PD, and in the end, a sexual assault case in which detectives from SVU were called in from New York.

The frenzy has been building for weeks.

News Channel 8 was there in Chicago as the cast and crew made the magic on location. We went behind the scenes to get the scoop and the secrets. One thing we quickly learned is that the actors love shooting the show in Chicago.

Jon Seda, who plays Chicago Police Detective Antonio Dawson, tell us, “Its feels authentic to be here, it makes it real for us. One day I was eating lunch and two officers from the real Chicago PD picked up the bill. That was cool, and the ultimate compliment.”

8 on your Side had a front row seat, watching the actors in action, just feet away as they shot scenes. They look and act like family, since so many of them live and work in the Windy City. And, when it comes to the combination of these crime show, hotter than ever, it’s like a high school reunion.

Everybody is thrilled to see each other. Actress Amy Morton loves her role on Chicago PD as the snarky, bossy and ultimately lovable, Sgt. Platt at District 21.

She tells News Channel 8, “I love doing the crossover because we’ve gotten to know those guys so well. So, it’s fun to be one someone else’s set.”

And, that’s a familiar sentiment.

It’s no easy task to combine all three shows, but the actors enjoy it so much that they look forward to the Crossover events each season. In fact, they often get together to watch the final product when the episodes hit the air on NBC.

Heartthrob Taylor Kinney who plays Kelly Severide on Chicago Fire shared with us, “We get the group together, and we’ll do popcorn and sodas and tweet with the fans, we have fun with it. Playing Severide is really my life.”

In fact, when the shows cross over in the intense storylines, there are all kinds of connections between characters.

Case in point: There are family ties between Chicago Fire and Chicago PD.

On Chicago PD, Detective Antonio Dawson plays the brother of Gabrielle Dawson, who just happens to play the role of a tough-as-nails firefighter on Chicago Fire. They star in scenes together in the crossover episodes as Gabrielle’s brother asks for help in the serial killer case.

Gabrielle, known as Gabby on the show, is actually St. Petersburg native, Monica Raymund.

Monica comes home often to the Bay area where she stays with her mother in Snell Isle, savors meals at Red Mesa and enjoys her favorite relaxation spot – St. Pete Beach.

As for the crossover, she loves it.

“My brother Detective Antonio Dawson who plays a detective on CPD,” Monica explained. “He’s actually the one who calls and tell us we can help out in the investigation in the crossover episodes. It’s an actor’s dream to get to work with so many talented people, especially Mariska Hargitay.”

Hargitay is a big part of the crossover episodes, as she is a long-time, key character on Law & Order: SVU, playing the role of Olivia Benson for well over a decade.

Monica shared with 8 on your Side a neat fact about meeting Mariska.

“She told me a long time ago when I first met her that I’d have my own show someday,” Monica smiled. “Now, she’s on MY show! It’s amazing. I love it!”

In the end, this crossover event centers around a case that ultimately captivates and connects all cast members from each agency in all three shows.

The storyline really is an actor’s dream and a fan’s wish – a wish that comes true for those both starring in and watching the NBC ratings triple threat – Chicago Fire, Chicago PD and Law & Order: SVU.