The FitzSimmons scenes on Agents of S.H.I.E.L.D. in the Season 3 premiere were emotional enough, and they somehow managed to top themselves this Tuesday. Thanks to a major team effort, Simmons is back on Agents of S.H.I.E.L.D. after her mysterious disappearance. The Kree monolith is destroyed and we definitely haven't heard the last of this mysterious planet with the copious blue lighting, but at least Simmons is safe and sound for now.
We also learned that Simmons isn't the first person to go through that portal. People have been sending themselves through it as a ritualistic sacrifice for decades, as demonstrated by a flashback with some English Lords. However, Fitz's ultimate discovery started with something small — a sandy residue that got onto his finger during his heartbreaking confrontation with the monolith. After determining that the substance was both alien and very old, the team had no choice but to consult their friendly neighborhood Asgardian.
Professor Randolph helped the Agents track down the castle in Gloucestershire that we saw in the episode's teaser, where the monolith was held for some time. In a secret room, we found a series of Frankenstein—esque machines that they thought could be used to control the portal. Eventually, Fitz figured out that it was set up like a sound system, which gelled pretty well with Daisy's Inhuman tuning fork power. Fitz jumped into the portal and ran around the planet in a storm before finding Simmons and just barely grabbing on to her in time to be whisked back up into the portal.
It's hard for me to believe that this terrifying planet was introduced just to be resolved and forgotten about so quickly. Will Simmons have to go back for something? What did she learn there? What, or who, does she need to stab in her nightmares? Why was it called "death" in Hebrew? We still don't know where, or even when, she was all this time. I'm as happy as anyone that FitzSimmons are reunited on Agents of S.H.I.E.L.D., but Jemma's return brings way more questions than answers.