One of the most commonly used phrases in analyzing stories is "Blink and you'll miss it" -a way to highlight the small details that make a work gel together beyond its big broad strokes. Tonight's episode of Marvel's flagship ABC drama "Agents of S.H.I.E.L.D." contained just such a detail that ended up paying off in the hour in a big way. But "Watchdogs" may prove to be a "Blink and you'll miss it" moment in a different way as this episode is the most overtly political story told in the Marvel Cinematic Universe to date. The only question is whether it will be the last.

Things start with everyone's favorite gruff mechanic Mack on a rare moment of personal leave after the loss the team suffered last week. While the audience has known little of Mack's personal life before now, the broad strokes fill in quickly. His younger hothead brother has spent the past several years taking over the family home and struggling to be the good son while his brother trots around the globe doing whatever secret things he never shares with them. There's love but also resentment, and amidst their attempts to catch up, the brothers do what so many others do: talk politics. Nearby, the previously mentioned but yet unseen hate group known as the Watchdogs has set off a massive bomb in an ill-advised protest against the government's perceived support of aliens like the Inhumans. Mack's little bro is feeling their message despite (or maybe spurred on by) his brother's warnings.

Back at S.H.I.E.L.D. HQ, a series of similarly personal conflicts swirls around the Inhuman debate. On one side, there's Lincoln - the rogue Inhuman doctor who's stuck around as a potential agent mostly because of his feelings for team player Daisy. When Director Coulson hold Lincoln back from a field assignment, it becomes clear that he doubts the doc's dedication to the S.H.I.E.L.D. cause. Meanwhile, Simmons and May work to get on the same page themselves on the mission to find Melinda's ex-husband/Inhuman serial killer Lash. Simmons blames herself for the monster's last killing spree, but when she realizes how May's own hunt can more quickly zero in on the renegade rogue, Jemma stops short of believing that the only way to end Lashes spree is to kill him.

But most of these issues are just the general spinning of subplots that comes with a soap-style superhero show. The real fireworks of the week are born from Mack, Daisy and Fitz's investigation into the Watchdogs bombing. Mack sees the growing tension with his brother get worse as he's called on to secretly get back on the job, and his feelings only coarsen when he clashes with Daisy over the reasoning behind the Watchdogs' existence. While he knows the group is deranged, hateful and dangerous, he understands why some people would be drawn into their influence. But true believer in the Inhuman potential for progress and freedom that is Daisy balks at the very idea. To her there's only one path towards the future: one where everyone lives out in the open as who they are.

Does this conversation remind you of anything? Did you talk about Donald Trump with your uncle at Thanksgiving? Sure, it's hard to put a specific pin in this episode of a superhero TV show and say "That moment right there is one explicitly meant to take a shot at a specific element of our modern politics." But the producers of "Agents of S.H.I.E.L.D." are obviously engaging with issues of extremism in America head on. The metaphor isn't a 100% match for our own world (like the X-Men, the idea of Inhumans as a superpowered threat tends to lose a 1-to-1 point of comparison pretty quickly). But as the Watchdogs episode went along, the focus on the personal elements of this debate made the political nature of the story all the more intriguing.

As the story moves along, those very real world issues recede a bit into the background. Coulson and Lincoln link the Watchdogs' activity to former S.H.I.E.L.D. Agent Felix Blake (played by all-star character actor Titus Welliver with his signature weariness) and go off in search of his plan. Meanwhile, Daisy uses the threat of torture to lead Fitz and Mack to the local Watchdog chapter's barnyard meeting where shit really hits the fan. Mack's brother arrives to check things out, the trio's cover gets blown, Fitz is tagged with an implosive compound (and/or Easter Egg to "Agent Carter") and Daisy has to use her powers to help the team escape. But tellingly, a stray Watchdog looks out into the murky night of the fight scene and says, "Did you see what that guy did?" It's a detail that many viewers probably missed or outright ignored, but as it turns out their attribution of Inhuman powers to a masculine pronoun was no mistake.

The story reaches its peak as Coulson and Lincoln face down Blake while Daisy attempts to save Fitz's life with more threatening. The scenes play out in parallel as Coulson mock pushes Lincoln to murder the man standing in front of them only to see Blake's image fade as a sophisticated hologram. It was all a test to see if Lincoln would go all-in for S.H.I.E.L.D. without losing his sense of self, and that the doc didn't truly go for the kill shot said everything Coulson wanted to hear. On the other hand, Daisy's "all or nothing" method of interrogation pays off for the second time in the episode. It's only the latest use of superhero fiction's regrettable practice of torturing its way through a plot without a look at moral consequences, but there's a glimmer of hope that the show will address this before too long. More importantly for the story at hand, we learn that the Watchdogs have gone after Mack assuming that he's the true Inhuman of the team.

As one might guess, the finale comes down to a "brothers vs bigots" shootout in the Mack family home. The scene lacks some punch as the nearly pitch black setting obscures so much of how the action works, a somewhat common problem on this show. Not everything can be "Skyfall," guys. Still, the rebuilding of the Macks' brotherly bond in the face of our Agent's coming clean with his job works to put a bow on the proceedings, and the late-episode tease that Blake is actually a wounded and angry leader funded by Hydra is a promising step forward.

But outside the boundaries of the show's action adventure serial, the episode may prove a pivotal moment for the MCU. There have been plenty of times recently where perceived political bias in superhero comics has blown up in political media. Just check the recent response to a "Captain America" issue that revived an immigration-hating group of villains. Similarly, the fact that the producers are using the Watchdog characters the exact same way they've been played in the comics for almost 30 years won't do much to those who watch this episode and feel it's openly criticizing aspects of our current presidential cycle. Of course, there's no evidence that this will even be noticed in the political media (an issue of an all-American comic book is an easier target for anger than a network action show for a whole slew of reasons), but as all the tension building through "Agents of S.H.I.E.L.D." is a prelude to the kind of story we'll see in "Captain America: Civil War" it's worth wondering whether that film will go as far with its overt political ideas and how that message will be absorbed over the next several months.

Whether the public at large blinks and misses this episode or not, remember how it played out. If cable news spends April 6 going apeshit over the next Marvel movie, you'll know what match lit the fuse.