Even its most ardent supporters would have to admit that Marvel's ABC drama "Agents of S.H.I.E.L.D." has often been lopsided. Some seasons, the show has actually divided its quality episodes right down the middle (think Season 1's slow start vs its strong finish or Season 2's killer Hydra arc vs it's meandering Inhuman saga). But so far, the series' fourth year on the air has been a odd mix of generally aimless world-building with some killer concepts and characters breaking through now and again. With its mid-season finale – tonight's "The Laws of Inferno Dynamics" – an action-heavy showdown did little to pull the spy show back on track.

The core of the episode is as straightforward as "Agents" mission-oriented adventures come. Ghost Rider Robbie Reyes' uncle Eli Morrow is on the cusp of attaining the crazy occult powers he's been searching after for a decade, leaving the uneasily reconstituted S.H.I.E.L.D. team will use the now unveiled android Aida to stop him. There's plenty of moment-to-moment action and twists to carry this narrative along, but perhaps it's more fitting to look at this finale storyline-by-storyline in order to judge where "Agents" is succeeding and where it's falling short at this point in its history.

To start on the upswing, the journey of the young Ghost Rider himself remains one of the most focused, affecting threads of the year. While Robbie briefly lost the curse that makes him the flame-headed Spirit of Vengeance last week, he's taken back on the mantle permanently in order to finish what he started. Because at his core, Robbie's journey this year has been less about vengeance and all about atonement. Whether he was taking down the gang members who crippled his brother or stopping his uncle from unleashing atomic Hell power, the character works to set things right even if it costs him his own life. That conflict boiled over when the Rider finally confronted his uncle – himself on a path of Vengeance driven by equal parts systemic bigotry and personal jealousy. The episode traps Robbie in his uncle's strange machine on the verge of death, which seriously caps the anti-hero's role in the action. But the pathos of the conflict is the strongest emotional content on display.

The flipside to the Rider's coin has been the deadend journey of Daisy Quake this year. While Season 3 ended with her defection from S.H.I.E.L.D., everyone's favorite Inhuman has been given little motivation or logic as she's walked her renegade path. By tonight, Daisy has essentially rejoined the team without ever really getting over whatever it was that held her back. Reequipped with her shockwave gauntlets and feeling the impending earth-shattering effects of Morrow's experiment, she spends the episode on the verge of saving the day while still stubbornly refusing to accept her role in superherodom until it falls in her lap when she's "outed" as being back in action with the media. It makes little sense and provides flat drama, which is a huge problem for the story of the second most important lead in the series.

The writers attempt to punch up Daisy's drama by tying her to Fitz, Simmons and the rest of the team's science gang. When the lovebird brainiacs figure out that Morrow has built a new version of the (actually real life) Demon Core atomic experiment in order to syphon energy from another dimension, they help launch the plan to stop him using Aida. The android woman has had question marks surrounding her since she absorbed the quasi-magical sci-fi knowledge of the Book of Darkhold, but any questions about her stability take a backseat as the hour leans hard into the show's standard "We're in the crunch zone with the fate of the world in the balance." Like most of Fitz and Simmons' story this year, the results are just average. The entire plot of hiding Aida and getting jerked around by new S.H.I.E.L.D. Director Mace did little to dig into the two fan favorites whose long-boiling romance was such a highlight last year. They're back to being the whiz kids in the lab, which makes for some fun effects when they team with (the temporarily sacrificed) Aida and Daisy to literally steal the floor out from under Morrow's machine but not much else.

The rest of the season-long subplots come off with just about as much electricity. Coulson and May work overtime to heal the wounds in the team, though none of the inter-agency intrigue really pays off as Mace completes a last-minute face turn. Mack and Yo-Yo's unspoken romance almost gets spoken, but the latter's guarded personality and tough gal attitude leave things a little underwhelming for the year's big ticket romance. And when Robbie sacrifices himself to zap his uncle into the demonic dimension, it completes the timebomb nature of the showdown, but everything feels like setup for some major story to come rather than the payoff of eight solid episodes.

Of course, it wouldn't be a mid-season finale without a last-minute twist. Sure, it seems like everything is fine on the surface. Our favorite team is back together. Their anti-Inhuman Senator foil has been batted away for the minute. Even prickly Director Mace seems ready to start playing the spy game in a way that works as he gives the go-ahead for more research into Life Model Decoys like Aida. But it can't all be sunshine and roses as Aida reconstitutes herself just in time to kill a S.H.I.E.L.D. Agent for some nefarious purpose. Whether this is the effect of the Darkhold or some self-awareness fallout after her painful undeath, we'll have to wait until 2017 to find out. But at the last minute, we find that the android has replaced Agent May with another LMD some time in the past.

The shocker is a bit underwhelming as it comes on the heels of such a flat story, but at least the concept holds great promise. "Agents of S.H.I.E.L.D.'s" very best moments have come when the series leans hard into its Marvel Universe espionage roots, and nothing fits that description better than a cabal of robotic double-agents trying to take down the organization from the inside. If the show can jettison its Inhuman dead weight, refocus the journey's of its ever-charming cast and give us some spy-fi storytelling madness next year, there may be hope yet for Season 4.