Chicago Med Boss on Crunch Berries and Hannah Asher’s Baby Daddy (Exclusive)

This article contains spoilers from the season 11 premiere of Chicago Med.

And then there were two. Parents, that is, of Dr. Hannah Asher’s (Jessy Schram) baby on Chicago Med.

After concluding the 10th season with a cliffhanger regarding Asher’s pregnancy, season 11 wasted no time answering whether the baby’s father was Hannah’s ex, Dr. Mitch Ripley (Luke Mitchell), or her bestie, Dr. Dean Archer (Steven Weber), whom viewers had not even seen Hannah kiss.

“It had to be Archer because, dramatically, that story had the most legs moving forward,” showrunner Allen MacDonald tells PEOPLE. “That was the story I most wanted to see Hannah and Archer experience emotionally.”

This future for them, he says, is based in their backstory: “As someone who came in in season 10, I watched the backlog of episodes, and their relationship — which started out bumpy and him not liking her — turned into this lovely friendship. And while I think it was a wonderful thing that those two characters could be friends, whether those actors intended to or not, I felt fireworks when I watched it. I felt this kind of attraction going on that maybe the characters themselves were not aware of or not willing to acknowledge.”

“Hannah is the only one who can strip Archer bare emotionally,” MacDonald continues.

He points to the last season’s 17th episode, “Book of Archer,” in which Archer’s ex-wife died and that reality hit him hard. “Asher gave him some real food for thought about the life he wants to live moving forward. And then at the end of the episode, she shows up at his door, and it’s supposed to be vague. It’s supposed to make you like, ‘There’s a vibe here, is it the vibe that we think it is?’ We left it hanging. And then we just played the rest of the season out, knowing that they slept together that night and that we would unpack that later because she ends up pregnant.”

In “Book of Archer,” Hannah brings Dean Crunch Berries cereal — and it’s the mention of the cereal in the season premiere that was intended to confirm that the baby was made that evening. But since when was Crunch Berries an aphrodisiac? (Don’t worry — we ask the hard questions so you don’t have to.)

“I don’t know,” MacDonald says with a laugh, “but my uncle, who sadly passed away a few weeks ago, loved Cap’n Crunch, and he always had it in his claws, even up until a few months ago, and the guy was in his nineties. So that was always a thing for me, and I thought, ‘Wouldn’t it be funny if Archer liked Cap’n Crunch?’ But I never liked Crunch Berries — it just seemed like too much — and I thought that would fit perfectly for him, a former military guy who eats healthy all the time but his one cheat is Cap’n Crunch. But no Berries because that’s just too indulgent.”

MacDonald adds, “When I thought of that and wrote, ‘I just never liked Crunch Berries because it was an indulgence,’ I actually made myself laugh, and that never happens. It made me giggle because I could see Steven Weber saying it.”

As for the future of the Archer-Asher relationship, “there’s nothing more intimate than having a child together, so that’s really going to shake up this idea that they can only be friends,” MacDonald says. “They were friends for a long time, they had a moment of connection, they slept together, and then the next day, I really believe that they had a conversation about, what does this mean moving forward? Are we better as friends or are we going to take this to the next level? And I think that they mutually decided that they wanted to remain friends. And I think that they really made an effort to stick to that, and they would have stuck to that. But if you rewatch the episodes from 18 to 22 last season, you can see Jessy Schram and Steven Weber playing the fact that [the characters] slept together. It’s like watching The Sixth Sense once you know the twist.”

The ultimate twist, though, is that MacDonald never intended for the season 10 finale to be a cliffhanger.

“When I wrote the finale last season, I thought that when Hannah knocked on the door and Archer answered and she said, ‘We need to talk,’ that was telling the audience that he was the father. And then I did an interview and was asked, ‘So are we going to find out in the fall who’s the father of the baby?’ And then I realized it wasn’t clear, so I just went with it,” he confessed.

While the showrunner wouldn’t share much else about the new parents’ future, he did warn PEOPLE not to expect a flashback to Asher and Archer’s hook-up any time soon.

“I thought about doing that for the premiere, but I think it plays better as a mystery for the time being,” he says.

Chicago Med airs Wednesdays at 8 p.m. ET/PT on NBC.