“Chicago Med” Boss Started with 3 Possible Baby Daddies for Hannah and Teases a Doc's 'Third Act' in Season 11 (Exclusive)

When play 11 of Chicago Med kicks off, there's 1 large bid of business: Revealing nan paternity of Dr. Hannah Asher's (Jessy Schram) baby. Is it pal, Dr. Dean Archer (Steven Weber)? Or is it her ex, Dr. Mitch Ripley (Luke Mitchell)?

Of course, that won't beryllium nan only play headed to Gaffney Medical Center this season. 

"The taxable of this play is that clip is moving out," showrunner Allen MacDonald tells PEOPLE. "For immoderate people, that virtually intends that they person a terminal unwellness and whitethorn dice soon. And for different characters, it intends I'm 65 years aged and I whitethorn beryllium astir for different 25 aliases 30 years, but really do I want to walk those years? Do I want to walk them doing nan nonstop aforesaid point I'm doing now, aliases do I want to person a 3rd enactment and alteration it up?"

The play 10 finale revealed that Dr. Caitlin Lenox (Sarah Ramos), nan caput of nan E.D., tested affirmative for an highly uncommon prion disease, Gerstmann-Sträussler-Scheinker (GSS), nan fatal illness that yet killed her mother — truthful that accounts for one of MacDonald's scenarios.

Below, MacDonald teases a fewer much gems to look guardant to this season, including nan return of Dr. Will Halstead (Nick Gehlfuss).

PEOPLE: Given your 3rd enactment change-up reference, does this mean we're going to spot a characteristic reasoning astir leaving medicine?

ALLEN MACDONALD: I wouldn't opportunity that we're going to spot a characteristic deliberation astir leaving medicine. I would opportunity that a characteristic is going to beryllium reasoning astir really they want to believe medicine, and perchance do they want to put their clip and attraction into mentoring and educating nan adjacent procreation of physicians.

I'm funny erstwhile nan determination astir Asher's baby's paternity was decided. Did you cognize each along, aliases did you determine complete nan summer?

That determination was made astir halfway done past play successful nan writer's room. We had talked astir it from nan get-go. We knew that early successful play 10, Hannah was going to person a very affectional and achy acquisition pinch a characteristic named Eloise, who has preeclampsia and dies soon aft childbirth. But that characteristic was going to inquire her successful that aforesaid section earlier each that happens — obviously, because dormant group don't inquire questions — "Do you want to person kids?" And that Hannah would, for nan first time, really person to deliberation astir it and go, "You cognize what? I deliberation I do." We knew that that was going to beryllium nan opening of her travel of nan season, and that was going to extremity pinch her becoming pregnant.

So early on, truthful we knew she was going to beryllium pregnant, and we talked astir who nan begetter was going to be, and location were 3 contestants. The first 2 are very obvious, it's Ripley and Archer. The different 1 was going to beryllium Dr. Will Halstead. And that would beryllium nan first clip you had seen him successful respective years, was that she would spell sound connected a doorway and that he would reply aft having not been connected nan show for 2 afloat seasons. But we decided that if we were going to bring Nick Gehlfuss back, we were going to do it successful a different measurement than that.

You can't do that to Natalie (Torrey DeVitto)! Fans request them to beryllium together.

Well, successful that type of it, they weren't.

Thank you for not going down that road. So erstwhile did you cognize if it would beryllium Ripley aliases Archer?

In nan writers' room, connected a dry-erase committee nether Hannah it said "baby daddy," and we had a large mobility mark. And 1 time I conscionable decided, and I walked down location dramatically. I went successful nan room and everyone stopped talking erstwhile I went complete and I erased it connected nan committee and wrote who it was.

So you brought up Nick Gehlfuss's return. What tin you stock astir that and erstwhile tin we expect to spot it?

I emotion Dr. Will Halstead. He's truthful messy. And erstwhile I went backmost and watched nan seasons earlier I sewage here, he was a characteristic that I conscionable fell successful emotion with, amongst others. I mean, I really emotion nan original cast. It's why I brought Dr. Sarah Reese [Rachel DiPillo] backmost past season, and why we're bringing Nick Gehlfuss backmost this season. And what I tin show you is that he drops by Gaffney to opportunity hullo to aged friends. He has Natalie's son, Owen, successful tow, and they're going to a Bears game, and it's Chicago Med. So if you deliberation it's that simple, it astir apt isn't. He pops up successful nan 200th episode, and it's nan first of respective episodes.

We were really sad to perceive astir Marlyne Barrett (who plays caregiver Maggie Lockwood) taking immoderate clip off. Is location immoderate update connected her return?

It is presently unclear. Marlyne approached america and said that she needed to return immoderate individual time, and we of people emotion her and support her successful doing that. And from a storytelling standpoint, I would emotion to person her back.

Chicago Med play 11 premieres Wednesday, Oct. 1 astatine 8 p.m. ET/PT connected NBC.