Agents of SHIELD just brought Simmons home, but the scientist is looking to fly the coop once more.

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After a long six months on an alien world, Jemma Simmons (Elizabeth Henstridge) spent "A Wanted (Inhu)man" attempting to adjust to the realities of Earth. From harsh noises to a different gravity, life back home is peppered with jarring reminders of just how long the agent was away.

Which is precisely why Bobbie and SHIELD fans alike were floored by the episode's post credit scene. Found examining the shattered monolith, Simmons uttered the words no one ever though she would say - "I have to go back."

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So, why is the scientist apparently hell bent on returning to a world that gives her nothing but nightmares? The truth will be revealed in episode 5, "4,722 Hours."

"She's completely back to square one trying to almost learn how to walk again, learn how to sleep again, learn how to eat normal food," Henstridge told Entertainment Weekly. "She's completely at zero, so it's going to take a second. She's really struggling. We'll definitely find out why she's struggling so much in later episodes."

In fact, viewers may even be treated to flashbacks. We've seen very little of her unidentified alien planet - Simmons' rescue was full of swirling dust and anxious nail biting - and Henstridge informed Entertainment Weekly that a wider view of that world is a very real possibility.

Get the whole story when Agents of SHIELD airs Tuesdays at 9 p.m. ET on ABC.

Tags: Marvel's Agents of S.H.I.E.L.D. television ABC