Jesse Lee Soffer shed some light on the state of the members of the Intelligence Unit once "Chicago P.D." returns on air for season 4.

In an interview with The Hollywood Reporter, the actor who portrays the role of Detective Jay Halstead revealed that all the members of the team will be "on edge" after unit head Hank Voight (Jason Beghe) lost his son at the end of the third season.

"Everybody's waiting to see what happens. Everyone's treading very cautiously, very lightly and Lindsay's (Sophia Bush) obviously having a really hard time," Soffer said. The actor added that the air in the first two episodes of the season will be thick with anxiety.

But while the tension within the unit affects everyone, Soffer revealed that the relationship between Halstead and Lindsay will grow stronger. "What's interesting is I think now, because they've gotten closer and the relationship's been going on for awhile, Lindsay is really going to rely on Jay and really lean on him this season more than others especially with what's just happened with Voight. So we'll see them get closer," he stated.

Also, the actor teased that the cases that the Intelligence Unit will deal with in season 5 will be very interesting. "We have some opportunities there to tell some interesting stories and to get into body cams and I'm sure that Dick doing ripped from the headlines is going to get into that so it will be really interesting for us," Soffer added.

There are also talks about a possible large-scale crossover happening in the upcoming installments of all the "Chicago" shows, including "Chicago P.D.," "Chicago Fire," "Chicago Med," and the brand-new "Chicago Justice" spin-off. The big crossover is expected to be included in the midseason plots of the shows.

"Chicago P.D." season 4 premieres on NBC on Wednesday, Sept. 21.