In newspaper comic strips, telling an ongoing story can be an incredible headache. There's no guarantee anyone will read every strip, and not every newspaper carries the strip every day of the week, which means every strip needs some degree of recap of what's happened and must advance the story so incrementally that a reader can miss a strip and not get lost. It's a massive headache, yet one that the best comic-strip writers make look effortless.

Increasingly, that's how I feel about ABC's Marvel's Agents of S.H.I.E.L.D. as it continues its way through a rip-roaring second season that seems designed to turn every single negative on the show into a positive through sheer force of will.

Agents of S.H.I.E.L.D. has gone from crushing disappointment to geeky delight

The series was originally set up as one that would play heavily within the continuity of Marvel Studios' movies, but that's become less and less true as the show has gone on. Now, it's almost completely walled off in its own corner of the Marvel Universe.

And it's all the better for it. Agents of S.H.I.E.L.D. has gone from a crushing disappointment to a geeky delight, a show that positively glows with love for both its source material and the creative restrictions necessitated by being a tiny part of a much larger world.

Being closed off from the Marvel cinematic universe has actually led to a better TV show

Agents of S.H.I.E.L.D. began as a sort of superhero X-Files. Every week, a team of S.H.I.E.L.D. agents (think of secret agents who deal exclusively in superpowered shenanigans) led by Agent Phil Coulson (Clark Gregg) got involved in all manner of mischief before wrapping things up by the end of the episode.

Despite having a comics universe that stretched back decades, the show seemed largely uninterested in playing around with Marvel lore. It was, instead, a painful bore and a chore to watch.

It was a painful bore and a chore to watch

About two-thirds of the way through season one, however, the series turned the team from well-funded government operatives to underdogs, a group on the run from evil agents within S.H.I.E.L.D. who wanted to wipe them from the face of the Earth. Here, finally, was dramatic tension. And here, finally, were stakes that gave the characters reasons to be there.

The show hadn't yet figured out how best to use everybody in its ensemble to maximum advantage, and it still couldn't tell a case-of-the-week story to save its life. But the overarching storytelling was thrilling, and the way the series turned allies against one another made for gripping viewing.

Of course, much of the audience had tuned out by that point. In season two, S.H.I.E.L.D. has felt as if it's mostly closed off from the Marvel universe at large. While the Avengers are preparing to battle the darkly villainous Ultron in their upcoming movie sequel, our intrepid agents on TV are in a completely different, backwater corner of the Marvel universe, investigating abandoned cities and reviving dormant powers.

There are connections to the Marvel cinematic universe (particularly when it comes to the upcoming film centered on the Inhumans), but they're so minor as to be easily lifted out of the Marvel Studios story as a whole, just like all those comic strips readers might not experience.

That separation from the larger Marvel cinematic universe has given S.H.I.E.L.D. even more drive than it had last season. The season took off like a rocket and has barely let up since.

Even with an obviously reduced budget, the show has greatly enhanced its action sequences through clever setups. It's brought ultra-obscure Marvel characters onto TV. And it's taken one of the previously non-super agents and turned her into a superhero, in a story that's one of the most daring rewrites I've ever seen.

The show is trying to make its terribleness seem like part of a plan

At the end of last year's midseason finale, Skye (Chloe Bennet), an elite hacker who seemed to exist mostly to annoy fans last season, was transformed into an actual Marvel superhero named Quake.

Since then, the series has admirably raced past the part where she tries to keep her new powers a secret from her friends to the part where she starts to realize she needs to learn how to control them.

In a recent episode, she learns that trying to repress her powers has only resulted in huge numbers of hairline fractures in her arms and burst capillaries that result in bruises. It almost serves as a metaphor for the show finally embracing the presence of superpowered beings in its universe.

Much of the first season was spent on mysteries surrounding Skye that even the show's most ardent fans had trouble caring about. Her parentage seemed of no real importance, and the way the show kept insisting she was one of the most important characters ever grew irritating.

But in season two, the show has daringly tried to suggest that everything that's happened over the course of the series — good and bad and god-awful — was part of a plan to get Skye to a place where she could be turned into Quake.

It's the kind of story turn that doesn't really make sense, but it's introduced a healthy dose of ambiguity into much of the series. Coulson and his fellow agents can't know for certain that they're not being manipulated by forces of evil, who aim to use Skye to their own ends. And as S.H.I.E.L.D. agents, they're supposed to ultimately subdue and deal with Skye, not keep her on as a friend and coworker.

Institutions, no matter how benevolent, inevitably dehumanize

Yet they can't bring themselves to do so. They're hurtling toward some sort of confrontation, her dragging them there, and they don't know how to stop the runaway train. It's given the season an intense momentum.

It also plays into one of the favorite themes of the show's co-creator, Joss Whedon. Whedon, who's perhaps most famous for creating the TV version of Buffy the Vampire Slayer and directing The Avengers and its sequel, has been a minimal presence in the history of S.H.I.E.L.D. But the show is staffed with people who've worked extensively with him, and its showrunners are Jed Whedon and Maurissa Tancharoen, who trained under him.

What they've done is commit to a pet theme present in all of Whedon's work: institutions, no matter how benevolent, inevitably dehumanize. Once you're part of a larger operation, you're simply a cog in the wheel, a plot device. It's only once you reclaim your own agency that you can create real change. But doing that is difficult. It involves standing in front of that runaway train and yelling, "Stop!"

The show still has problems with its tone and single-episode stories

S.H.I.E.L.D. still has an imperfect tone, occasionally crossing the line between camp and over-the-top cheese. (This is something TV's best superhero show, The Flash, avoids with aplomb.) The directorial style of the series remains rather staid, forever cutting around the action rather than showing it up front. And the series still seems aware it has a few charisma sucks in its cast, so it's started throwing guest stars at the problem, hoping that having enough recognizable faces popping up will be enough.

The series' biggest problem remains its utter inability to tell a single-episode story in a truly compelling way. The only stories that really work here are tied into the overall serialized plot. That's fine as these things go — and both modern TV and modern comics are heavily serialized mediums, generally — but one leaves many episodes excited for whatever's coming next while still feeling a bit undernourished by what just happened.

The series' biggest problem remains its utter inability to tell a single-episode story in a truly compelling way

But you know what? All of these patch jobs over everything else kind of work, and giving the characters goals to pursue and momentum to ride has helped formerly listless actors like Bennet find another gear. Serialization is often a crutch in modern television, brought in as a last resort to prop up go-nowhere episodic plots, but it's a crutch that usually works, especially when it's deployed with as much finesse as it is here.

At its best, S.H.I.E.L.D. suggests that everything you're seeing — good and bad — is part of a grand master plan, and that if you sit back and enjoy the ride the pieces will fit together eventually. There was a time when actually believing the show was capable of such storytelling wizardry was laughable. That it's possible to take the show seriously now might be its greatest achievement. Now we'll see it can keep it up.

Marvel's Agents of S.H.I.E.L.D. airs Tuesdays on ABC at 9 pm Eastern. Several episodes are also available on Hulu.