Chicago Fire, Chicago Med and Chicago P.D. are coming together for an epic two-night crossover event. It kicks off with Chicago Fire's episode on 5 January at 9pm ET, continuing with Chicago Med at 10pm ET, and concluding with Chicago P.D. on 6 January at 10pm ET on NBC.

The official synopsis released by NBC reads as follows:

Following a knife attack, a member of the team lies in peril and their condition takes a sudden turn for the worse, leaving Dr. Connor Rhodes (Colin Donnell) and Dr. Toni Zanetti (guest star Julie Berman) scrambling to race against the clock. Word quickly spreads that some of Connor's fellow doctors feel he should have operated sooner, causing tension at the hospital. Dr. Natalie Manning (Torrey DeVitto) makes preparations for her pregnancy and Nurse April Sexton's (Yaya DaCosta) brother (guest star Roland Buck III) struggles through his first day at the hospital. Meanwhile, members of the Chicago P.D. Intelligence Unit help investigate whether the case of a women clinging to life after Firehouse 51 pulled her out of a burning building is attempted suicide or murder. As the investigation deepens, a surprising parallel to other patients surfaces.

Click here to watch the special episodes live via NBC. You can watch Chicago Fire's episode online by clicking here and the Chicago Med episode by clicking here. To watch the last hour of the crossover event featuring Chicago P.D. you can click here. These links can only be viewed in the US.

Get your fill of all things Chicago during the biggest #OneChicago crossover yet!

Posted by Chicago Med on Monday, 4 January 2016

Executive producer Matt Olmstead discussed what to expect in the three-show crossover event. Olmstead told Entertainment Weekly, "We're starting with Fire in the 9 p.m. hour on Tuesday, switching with Med. They respond to a fire where a woman looks like she may have been trying to commit suicide. We're not quite sure. When we take her to Med, her levels are all off. It's a medical mystery, which throws us into the Medhour."

The producer dished on the special episode's plot and explained, "It kicks off into a much larger medical story based on a headline late last year, where a doctor was misdiagnosing and over-prescribing cancer medicine, chemo in particular. While figuring out what happened, more women come forward as we start to peel back layers of how deep this goes. Ultimately, it's thrown to P.D., because it's a criminal investigation, a very hard one to prove because the burden is there was an intent to have these people killed."

The episode will feature a big revelation for Chicago P.D.'s Hank Voight (Jason Beghe), Olmstead said, "Through that is the revelation for Voight that his late wife, who we've established on the show passed away from cancer, the last doctor she ever sought treatment from is the guy who's in their crosshairs. So, it's Voight basically investigating and wanting to have answers in terms of not only the current victims they're encountering, but his late wife as well."