The two-night crossover event airs on 28 April on Tuesday's episode of Chicago Fire and continues through Wednesday's back-to-back episodes of Chicago P.D. and Law & Order SVU.
The three NBC shows are coming together to find a multi-city serial killer when he possibly strikes again in Chicago.
The three-episode event begins on 28 April, when firehouse 51 discovers that a woman they pulled out of a fire was actually brutally raped and left to die.
In the second hour, Benson (Mariska Hargitay) travels to Chicago where she works with Chicago PD to track down the man responsible for many past murders in New York under the Sergeant's tenure.
"There's something about the alchemy of these shows coming together that really makes it crackle," executive producer Matt Olmstead told TVGuide.
"This crossover is the best [crossover] yet and provided the best episode of Chicago P.D. yet. The cool thing about this one is ... that it starts in Chicago and stays in Chicago in the 9pm hour with SVU people over there. Then, at 10, it goes to New York with our guys going there. So it plays like a 3-hour movie without ping-ponging back to particular cities for the timeslots."
In an interview with Entertainment Weekly, Matt Olmstead teased a major character's death in the episode.
"We've got a great bad guy and one of the characters in P.D. doesn't make it out alive, unfortunately," he teased.
Law and Order SVU executive producer Warren Leight explained that while planning this crossover, all the producers on all three shows strove not to repeat themselves, and wanted a good reason for the three squads to intersect.
"I didn't just want it to be a drop-in," Leight said, noting that the case is somewhat inspired by "the horrible and successful arc of Ted Bundy, a guy who got away with dozens of crimes in multiple locations for a long period of time because no one could believe he could do something like this and no one put the pieces together."
The Chicago Fire, Chicago P.D. and SVU crossover event kicks off on 28 April at 10pm and continues on 29 April at 9pm on NBC.