The upcoming episode of NBC's "Chicago Fire" titled "The Beating Heart" may witness a mega crossover between other two series namely "Chicago Med" and "Chicago PD."

Though there are not many details available regarding the information, Carter Matt has reported that fans can anticipate "at least one catastrophic event" to be the centre of Episode 10.

It has also mentioned that the crossover will be a two-episode story arc which will surely shock the fans.

In an interview with The Hollywood Reporter, Matt Olmstead, creator of the show, had said that the crossover story will revolve around Hank Voight's (Jason Beghe) life.

"It does bring all three shows together," said Matt Olmstead. "The one personal piece of storytelling it unearths is Voight's back-story with his late wife. We've established that she died years prior to when he appeared on 'Fire,' but not the circumstances of her death and what Voight has to deal with in terms of dealing with that memory."

He further said that the story will also affect Lindsay because she always looks at Voight's wife as a perfect role model than her own mother, Bunny.

"It really hits them both hard and it's a nice window into Voight's relationship with his late wife," he said, "That was so meaningful and profound that when she died, we don't establish him dating. He had the little flirtatious crosses with Mariska's character on 'SVU,' but that was his one love, true love, only love."

Olmstead also talked about another crossover which will involve "Chicago Fire," "Chicago Med," "Chicago PD," and "SUV." He said that right now, the project sounds too ambitious, but it might take place if the first crossover generates some positive results.

In the previous episode titled "Short and Fat," Patterson fills in for Boden, who's trying to clear his name. Severide learns where Serena may be hiding while Herrmann and Otis give Freddie a job that keeps him close by.

Season 4 will continue from 5 January, 2016 after the winter season break is over.