Season 4 of Agents of S.H.I.E.L.D. has seen a whirlwind of change. In addition to welcoming a new S.H.I.E.L.D. director, in Jason O'Mara's Jeffrey Mace, the series dipped its toe in the mystical lake of the Marvel Cinematic Universe by welcoming the Spirit of Vengeance to television for the first time. The effort was impressive, as much for its visual effects as for its choice to move away from the ongoing Inhumans storyline. But the trip to the supernatural side of Marvel's ever-expanding universe was short-lived (because flaming CGI skulls are expensive), meaning the second half of season 4 would shift to a storyline involving Life Model Decoys, something co-creators Jed Whedon and Maurissa Tancharoen had wanted to include in an earlier seasons.
But the wait to delve into the world of artificial intelligence and LMDs proved to be for the best, as the writers discovered that, in beginning the season with the disparate and mystical Ghost Rider arc, they had the perfect way to introduce the LMD Aida and continue with Holden Radcliffe's story. As it turns out, segueing from supernatural forces to hard science fiction made more sense than might have seemed possible at first glance.
During the 2017 TCA Winter Press Tour, Whedon addressed the timing of the LMD storyline, as well as how Ghost Rider opened the door for the AI revolution:
"It's something we wanted to do for a long time. When you start a show called Agents of S.H.I.E.L.D. you're pretty sure you're going to do it at some point but we always have to steer away from stuff that's coming up in the movies and there was going to be some robots in some of those big movies, so we steered away from it initially but we always had it in our minds. We felt that we had a lot of good Inhumans stuff to do last year so it seemed like the right time.
When we started talking about Ghost Rider, we realized that with the Darkhold there was a way to get all of these things in one sort of soup, and so that's sort of how it happened this year."
That soup, as it turns out, will have one more key ingredient thrown into the pot before the season comes to an end, as the second half of Agents of S.H.I.E.L.D. season 4 will eventually focus on a third story connected to both the Ghost Rider and LMD arcs. Whedon said:
"This year there's three [story arcs]. It's based on our schedule of how we're airing. We like to run continuous, if that [is] possible, so this next [LMD] chunk will be a section and then we'll be off for a while and there'll be a third part."
While no details were given as to what fans might expect from this third part, Marvel TV president Jeph Loeb said, "It's all connected." Tancharoen followed Loeb's comments up by saying, "Connective tissue will remain apparent through all three parts," which should leave viewers on the search for the next likely thread to emerge during the LMD storyline set to kick-off (in an official capacity, considering where the midseason finale left things) with 'Broken Promises'.
What that third storyline will entail is anyone's guess, but considering the juicier role that Jeffrey Mace has yet to play – either in his capacity as S.H.I.E.L.D. director or as his super-powered alter ego Patriot – it would be a safe bet he will factor into the intrigue that's yet to unfold.
Agents of S.H.I.E.L.D. season 4 continues Tuesday, January 10 with 'Broken Promises' @10pm on ABC.