This season Agents of SHIELD has been enormously better than last season, and I've actually enjoyed watching the show. It's not great television, but as an ancillary Marvel Cinematic Universe product it's pretty good. What's more, the show has reorganized itself in a way that indicates it could get even better in the future, if given a chance to live (the ratings are apparently not so great this season). One of the ways the show has improved is that it dropped the Freak of the Week format and has embraced a more longform storytelling structure, with SHIELD and Hydra both competing to understand a strange alien obelisk that ties into the origin of SHIELD hacker Skye. That story has been slowly, but satisfyingly, moving forward, and the latest episodes of the show have revealed that the obelisk isn't a weapon but rather a key to a temple in a hidden city. Now SHIELD and Hydra are racing to find that city and the temple and unlock its secrets.
Whatever those secrets are they're related to the alien Kree, the race to which Ronan the Accuser belongs in Guardians of the Galaxy. There's a Kree corpse that has been instrumental in the show, as its biology has been used to bring Coulson back to life after he was killed in The Avengers. The corpse is ancient - we're told it predates the pyramids - and in the latest episode of the show we learned that the Kree came to Earth millennia ago to judge and possibly destroy humanity. All of this ties into a very core aspect of Marvel Comics mytholigy - the Inhumans.
In the comics The Inhumans were the result of genetic testing by the Kree, who were enmeshed in a war with the Skrulls and wanted to create an army, as well as stop their own evolutionary stagnation. They learned that humans had genetic potential given to them by the Celestials (the giant planet-scouring guys in Guardians), and after monkeying with human DNA they were able to create this new race. The Kree eventually gave up on The Inhumans, who created their own culture away from humanity. They settled in the city of Attilan, originally in the North Atlantic but eventually moved it to the Himalayas and the the far side of the Moon. The Inhumans are normal humans until they are exposed to Terrigen Mist, which causes them to mutate in unpredictable ways. Some become monsters, some get incredible powers. It's all very hit or miss.
Attilan is like the number one secret city in the Marvel Universe, so when combined with the ancient Kree influence it makes a lot of sense that the Agents of SHIELD are headed towards Attilan. But will Marvel really debut the stars of their next Guardians of the Galaxy-type franchise on TV?
It's important to remember that the Marvel TV and the Marvel movies teams are separate. Kevin Feige doesn't have anything to do with Agents of SHIELD, something reiterated to me again and again by high-ranking Marvel people. The movie side will have a lot to do with Agent Carter, but SHIELD and the Netflix shows are pretty much off on their own. And the movies have, without a doubt, staked a claim to The Inhumans - their movie is coming out in 2018. So would the movie side of Marvel want the concepts and characters of The Inhumans introduced on this low-rated TV show?
Maybe. It seems likely that Scarlett Witch and Quicksilver will be Inhumans in Avengers: Age of Ultron, and Agents of SHIELD has showed that Hydra has definitely been playing with the DNA of possibly-Kree related people. Since Hydra appears to have activated the Twins' powers, this all fits. But there's no way that the TV show is going to be allowed to introduce a single Inhuman who will have a role in the movie, and there's no chance that Attilan will be first presented on a TV budget. Which means this promising storyline on Agents of SHIELD is certainly about to fizzle.
What I guess is that the team will find an abandoned city, with the inhabitants of Attilan having moved to the Himalayas or the Moon, but we won't find that out. We'll just know they're gone. Maybe someone will use the term 'Inhuman,' but in an Easter Egg-y way: "I've become something.... Inhuman!" someone will say after getting dosed by Terrigen Mists or Kree blood. And maybe this season, with its focus on Hydra DNA experiments, will feed into Age of Ultron, which opens with The Avengers shutting down Hydra bases (crossovers tend to be lowkey, but I suspect that Baron Strucker, the Hydra leader in the opening of Age of Ultron, could show up in the back half of SHIELD season 2). That in turn feeds into The Twins, so who knows - maybe Skye is an Inhuman, and Marvel movies is giving TV more access to their toys than I ever expected.
Whatever happens, there's no chance that Black Bolt or the Inhuman royal family shows up on TV this season (or maybe ever). Maybe this is the beginning of a better working relationship between movies and TV that could make Agents of SHIELD feel less like the adventures of people with a tertiary connection to the superheroes. Between the Kree appearing and a casual namedrop of Micro (The Punisher's tech guy), Agents of SHIELD is finally finding its place in the Marvel Cinematic Universe.