'Agents of S.H.I.E.L.D.' season 4 release date, spoilers & plot news: EP hints that upcoming episodes will focus more on FitzSimmons storyline

Leo Fitz (Iain De Caestecker) and Jemma Simmons (Elizabeth Henstridge) will try to work out a rough patch in their relationship when the back half of ABC's "Agents of S.H.I.E.L.D." season 4 premieres next year.

Also known as FitzSimmons, the fan-favorite couple had a complicated journey before ending up being together. Fitz had to deal with a brain injury, Simmons was abducted by the monolith, and other factors tried to keep them apart. In season 3, the two British scientists finally became involved in a romantic relationship.

Moving forward to season 4, the relationship was still important to both Fitz and Simmons, but their dedication to their work as members of S.H.I.E.L.D. began to eclipse their relationship. Fitz usually worked alongside Dr. Radcliffe or Coulson, while Simmons got a promotion and had to leave the science department. However, the two characters will soon be reunited when the series returns in a few weeks with a new episode.

Executive producer Jed Whedon recently caught up with Entertainment Weekly, and he revealed some interesting teasers about FitzSimmons and how their relationship will play out in the story. He promises fans that the duo will have more time to work out the complications in their relationship.

"They're suffering a little bit from working with the person you're with," Whedon explained in the publication's Spoiler Room segment. "We want to make sure that we get to see them just be together and be FitzSimmons of old. That doesn't mean there aren't still bumps in the road ahead, but there's a reason these two are together, and a reason the audience is rooting for them. So they'll get over their bumps in the road and we'll spend some time with them just being a couple and enjoy working together," he went on to say.

The fourth season of "Agents of S.H.I.E.L.D." returns to the airwaves on Tuesday, Jan. 10, at 10 p.m. ET on ABC.