Warning: spoilers ahead for Episode 14 of Agents of S.H.I.E.L.D. Season 5, called "The Devil Complex."
Season 5 of Agents of S.H.I.E.L.D. hasn't given the good guys much of a break from the very beginning. In fact, the only real respite that the characters have gotten to enjoy was the wedding of Fitzsimmons in the 100th episode (which also happened to confirm a huge fan theory), and even that was marred by the fact that Yo-Yo couldn't attend due to her recent de-arming courtesy of Ruby. The agents successfully retrieved gravitonium at the end of the previous episode, and they could theoretically use it to close the fear dimension that posed a very great threat to humanity. They just needed Fitz to figure out how to do it.
"The Devil Complex" proved that nothing in Season 5 is simple or straightforward as the agents were betrayed by one of their own in a devastating way that could lead to the destruction of the world. Fitz turned on his friends and crossed a lot of lines.
Fitz, Simmons, Daisy, Mack, Yo-Yo, and Deke were left in the Lighthouse while Coulson and May attempted to spring a trap on General Hale. An astronaut like the one from Maveth turned up at the Lighthouse and attacked Simmons, proving the the fear dimension was spreading its influence farther and farther. Shutting that dimension off became the top priority problem, and one that only Fitz could really solve. Unfortunately, Fitz was not dealing with the stress and pressure well, and the situation was not helped when the fear dimension manifested a version of the Doctor -- a.k.a., Fitz's doppelganger from the Framework -- to mess with Fitz and hunt down the two Inhumans in the building.
That's how it seemed at first, anyway. Agents of S.H.I.E.L.D. managed to pull off a very tricky move as viewers were led to believe that the Doctor was in the mix, attacking Deke and Mack before knocking out Daisy and strapping her to a table. Fitz seemed to be on the verge of a mental breakdown as he pleaded with the Doctor not to hurt Daisy... and then Daisy, weeping and in pain, asked who Fitz was talking to. Simmons figured out what was happening as well, and she raced to stop the hallucinating Fitz, who was actually the one doing all the terrible deeds for one terribly pragmatic reason: the only way to manipulate the gravitonium was for Daisy to use her powers, and Daisy couldn't use her powers due to the implant in her brain courtesy of Kasius.
Fitz, channeling his inner Doctor and ignoring the tearful pleas of his wife and his pal Daisy, just went ahead and removed the device from Daisy's brain in a move that could have paralyzed her permanently. When he didn't paralyze her, he shot her up with adrenaline to reactivate her powers right away. She did manage to manipulate the gravitonium and shut off the fear dimension, at which point Fitz knelt down and put his hands behind his head, surrendering to arrest.
Well, the good news is that there's no longer a fear dimension leaking monsters and mayhem into the real world on S.H.I.E.L.D. The bad news is that Fitz has suffered a mental break that had him acting as the Doctor, he doesn't regret his actions, Simmons kinda sorta signed off on his actions because she believes they need to do the unthinkable to try and break the time loop, Daisy has her potentially planet-destroying powers back, and she knows that she can use them to manipulate gravitonium.
S.H.I.E.L.D. has already hinted that gravitonium has something to do with how the Earth is destroyed in the original timeline from the beginning of the season; if unstable gravitonium is on the verge of ruining everything, Daisy might feel compelled to try and use her powers to stop it. She could very well accidentally destroy the Earth because she was trying to replicate the process Fitz forced her into in "The Devil Complex."
Are we 100% sure that Fitzsimmons aren't cursed? Really, the only good news to come out of the episode was that Deke has memories of his mom telling glowing stories about her father as the best man she ever knew. If Fitz never returns to himself after his mental break, he surely couldn't become the wonderful man so beloved by Deke's mom. Deke's very existence indicates that Fitz could recover. Then again, Simmons' vomiting at the end of the episode is likely a sign that she's already pregnant, so we can't be too confident of anything. Maybe Fitz never recovers, and Deke's mom only knows wonderful stories about her father because Simmons told her.
We'll have to wait and see. For as much of a bummer as it was to see Fitz turn on his friends, "The Devil Complex" was a pretty fantastically written and acted episode. Sign me up for whatever comes next! Tune in to ABC on Fridays at 9 p.m. ET for new episodes of Agents of S.H.I.E.L.D. We have to hope that the show isn't on the verge of cancellation, but at least we can rest easy in the writers' plan if the worst should happen. For a rundown of the network shows that have gotten the axe, take a look at our breakdown of TV cancellations and renewals. If you're still looking for new shows to watch, our midseason TV premiere guide and 2018 Netflix schedule can help your out.