Agents of SHIELD found itself exploring areas of the Marvel Cinematic Universe that the films have yet to tread in the mid-season finale, seemingly beginning to introduce audiences to the idea of Inhumans, a race of human like people that, once exposed to the Terrigen Mists, undergo Terrigenesis and transform into something else, often gaining super powers.
"Aftershocks" picks up that thread and runs with it, dealing with the aftermath of Skye and Raina's exposure to the Terrigen Mists. No one really knows what happened in the chamber, and a particularly nervous (almost manic) Simmons is insisting on putting Skye in quarantine to avoid any chance of an infectious alien disease spreading. She makes her feelings on those with unnatural biology perfectly clear here - after having seen the negative effects of exposure to alien biology time and time again, she is now firmly in the mindset of eradication rather than study, claiming that the risk is too high. It's a nice development for the character, partially playing on her actions in last seasons "FZZT", in which she attempted suicide rather than running the risk of passing an alien infection from herself to other members of the team.
Fitz has a very different reaction to Skye than Simmons did though, instead throwing caution to the wind and simply trying to help someone who has found themselves uncertain about who they are now, a situation he knows all to well. The difference in reaction to potential super humans is really interesting when you consider the upcoming slate of Marvel Cinematic Universe films - could the show be planting the seeds for a large scale disagreement on the registration of super powers? It would be way too cool if Agents of SHIELD was building towards Captain America: Civil War already, but a man can dream.
Raina's story is much less developed, simply choosing to show us what she looks like now and putting her in place for later episodes. The same is true of the small vengeance story involving Hunter and Bobbi, which is over almost as quickly as it starts in a move that feels like the show wanting to get something out of the way quickly to focus more on other areas. I'm not complaining as such - a brief cameo from the scientist last seen in the post-credits scene of Captain America: The Winter Soldier was enough to indicate that this is a plot thread that isn't over just yet - but it is somewhat of an anti-climax.
For the first time, Agents of SHIELD seems to be creating plot threads for the movies to follow rather than simply reacting to the events of the films, which can only be a good thing for a show that despite all it's improvements, has been criticised (often fairly) for it's lack of purpose. It will be interesting to see how the second half of this season interacts with the upcoming Avengers: Age of Ultron or the Daredevil TV show, if it even does, and I am quietly hoping for a Spider-Man episode now that Marvel have got the opportunity to use him. Between the constant development of the Marvel Cinematic Universe that is happening both on and off the show, Agents of SHIELD has got a real opportunity to make itself matter in the long run, an opportunity that I have confident it will start to capitalise on.