"Chicago P.D." returns in the fall with a few answers from the Season 3 cliffhanger finale of "Chicago Fire."

In the last episode of "Chicago Fire," Matthew Casey (Jesse Spencer) went missing at the same time that a dead stripper was found in his apartment.

Executive producer Matt Olmstead tells TVLine the shows will overlap when they return in the fall. We might find out what really happened to Casey in the cop spinoff as Chicago police investigate the case.

"That's what we're dealing with now that staggered start," Olmstead said. "Obviously, both shows exist in the same universe. We'd definitely have to deal with any kind of cliffhangers on the first one up."

P.D.'s Hank Voight (Jason Beghe) and Antonio Dawson (Jon Seda) are also involved in Casey's twisted ending, and the case will have to be resolved in the cop spinoff.

"I think we're going to have to, unless you drop them into some kind of space-time wrinkle, which is not the preference here on our end," Olmstead said. "It is a cop story, anyway."

Meanwhile, Olmstead hints that Fire's Gabriela Dawson (Monica Raymund) will be angry at Antonio for what happened to Casey. In the last episode, it may have been hinted that she is pregnant by Casey.

"There is some blame to go around, especially as it relates to Voight," Olmstead said. "Voight goes and gets Casey to step up, and it goes south. I don't think even Voight knows the full depth of what's going on in this place.

"But that's to be dealt with down the road. Obviously, the first concern is: Where's Casey?".

Will they ever find Casey? Who murdered the stripper and why?  

Fans will also see how the crew is dealing with the death of a close friend, Nadia (Stella Maeve). In Season 2, Erin Lindsay (Sophia Bush) hit rock bottom, and now everyone will deal with their own grief. Will the team break because of this tragedy? Or will they only get stronger?

Tune into NBC when "Chicago P.D." returns in November to find out.