"Chicago PD" season 4 episode 16 titled ‘Emotional Proximity' will feature a crossover between the original series "Chicago Fire" and its spinoff "Chicago Justice" to investigate a case of a huge fire leaving Olinksy's daughter in serious condition. The intelligence is determined in capturing the suspect.

"The team hunts the arsonist responsible for the massive fire that left Olinsky's (Elias Koteas) daughter in critical condition," reads the synopsis for "Chicago PD" season 4 episode 16 via TV Guide. Voight (Jason Beghe) will be the one to open the case with his team's support and Assistant State Attorney Stone's (guest star Philip Winchester).

Firehouse 51 is scheduled to examine how the massive fire started and hoping to find some clues that will lead to the person who did it. In "Chicago PD" season 4 episode 16, the team will learn the connection between the people in the building and its owner, which can produce a list of possible perpetrators since it was revealed that the massive fire was premeditated.

The massive fire started when a factory was destroyed by fire, leaving workers trapped inside and Olinsky's daughter is one of the victims, who is in critical condition. Voight finds the case very different from the previous one he's been with as it involves emotional turn of events especially that Olinsky has to deal with his daughter's serious condition because of the fire.

Reports say that apart from the crossover between "Chicago Fire" and "Chicago Justice" with "Chicago PD" season 4 episode 16, "Chicago Med" will also be included in the crossover, which will feature some of its characters in the series. This case appears to be of such importance as several departments of Chicago are involved in this and it's still unclear whether or not Olinsky's daughter will make it following the traumatic massive fire.

Showrunner Dick Wolf told the Hollywood Reporter that the crossover of "Chicago PD" season 4 episode 16 between "Chicago Fire," "Chicago Justice" and "Chicago Med" involved a lot of preparation. It will also feature Ruzek's (Patrick John Flueger) next steps after making a comeback to the intelligence unit.