In a tense moment in this week's episode of ABC's Marvel Studios drama "Agent Carter," crooked FBI heavy Vernon Masters stared down our hero with an assessment of the glass ceiling shatterer that sounds like a compliment but isn't meant as one. "Jack Thompson thinks very highly of you. He says that you're quite the independent thinker," Masters says. "You seem like the type of lady who doesn't play anything safe." The moment is as apt a description of the character as we've seen yet, and it slides neatly into place in "Smoke & Mirrors" -the latest strong hour in the generally slow simmering second season.

But if the appeal of "Agent Cater" is the idea that fans know exactly the type of lady Peg is, the draw to this week's installment is the show's revelation of how she got that way. Yes, the episode plays the part of "secret origin" for the character, but despite the clickability of that headline, the real creative draw here is about what Peggy's pre-spy days say about her in comparison to this season's big bad - the similarly backstoried Whitney Frost -and where the battle between the two will lead in the weeks ahead.

The hour opens with the kind of Peg we know and love, if a little smaller. As a child, the future agent Carter wraps herself in the trappings of a knight defeating a dragon and saving a princess. The scene is about as blunt an in as you can imagine to the story, but it takes a sweet turn as Peggy's brother Michael arrives in the flashback. Rather than taunting her or trying to hold her back, Michael teasingly urges his sister to action even as their mother swoops in to admonish her daughter for a failure to act more "ladylike."

In the "present" (this is a period drama, after all), Peggy doesn't seem to have taken mother's advice. Sloppily spilling her sandwich over scientific schematics and flirting with the intangible Dr. Wilkes, the adult Agent Carter is carefree and headstrong all at once. This is the show's bread and butter, of course, but it remains successful because the results of Peggy's take charge nature are always fun to watch. While chasing down information on Frost, her would-be senator husband Chadwick and the two-bit goon Rufus Hunt whom they hired to kill Peg last week, Carter and Jarvis don't do much to break open the mystery of Zero Matter or turn the tables on the bad guys in a major way. But what they do get to do is pile another half-dozen one-liners and action sequences on the show's already impressive pile. If all this series was was a procedural featuring Peggy tranquilizing Hunt, locking him in a trunk and then bluffing infecting him with an incurable disease, it'd still be one hell of a ride. But luckily there's more than meets the eye here.

The episode goes deeper as mad scientist turned movie star Frost gets her own backstory rolling in parallel with Peg's. Raised in the dustbowl of Broxton, OK (at the very least a fan service wink to Marvel's Asgardian history with the town if not a deliberate setup for future stories there), the woman then known as Agnes Cully had every bit as tough an upbringing as Peggy's seemingly charmed life in England. Agnes' mother sleeps with their landlord to keep a roof over the Cully's heads while the lecherous sugar daddy encourages the budding science whiz to smile more (vomit).

Flash to our current story where the cunning starlet has recently used her Zero Matter-fueled powers to literally eat away at one man in her current life set on using her much in the same way her mother was once used. But now Whitney can put her mind to the problem of the terrible power that's increasingly widening the black crack mysteriously set in her forehead. As Frost begins to experiment with a crate of lab mice to see just how the icky black goo that flows out of her can be harnessed, her eyes flash with increasing amounts of awe rather than horror.

Like all episodes this season, things in the A-plot work to collide by the hour's end with just enough complication and closure to keep the audience engaged for another week. Peggy and an unwilling Sousa finally catch a break in their investigation into the shadowy Arena Club thanks to her enhanced interrogation of Hunt (stunningly overused and ethically dubious faux-torture trope aside). But before they can get a warrant to break into the place where the cabal of ultra rich assholes meet and plot world domination, they're sidelined by Masters. The older G-Man is almost stupefyingly in the pocket of the villains, but the show pivots away from that idea by letting him threaten Peg with a Communist label. The shades of McCarthyism are a fine fit for the period and the LA locale, though one wonders if the show is really interested in developing that thread into anything more substantial. In any event, the threat is enough to push Peg and company in a different direction as they release a bugged up Hunt into the wild in order to glean more concrete evidence against Chadwick and Frost. What they get instead is an audio glimpse at Frost's powers -a moment that falls slightly flat as the horrific birth of a supervillain but at least changes the status quo to put the evil cards squarely in Whitney's hands over her dim-witted husband. No, our heroes are no closer to understanding the problem (Wilke's flashes of a Zero Matter vortex also tease but don't yet reveal anything significant), but at least the danger their facing takes on a new sense of urgency.

Though as much as that development sets up an eventual showdown between the two factions, the competing flashbacks are the real heart of the episode. In Peggy's past life, the woman we love to see fight back seems downright domestic. She takes a safe job code-cracking as part of the early War effort in England. She gets engaged to a pretty but boring officer who's in love with the privilege of office work. In short, she's everything her mother wants her to be. Peg's compliant status is underscored by her wardrobe -a calming sea of blue fabrics that provide a sharp contrast to the bright red hats and hot pink blouses of her SSR life. When past Peggy is offered a chance to train as a field agent, she turns it down as a preposterous suggestion until her brother Michael resurfaces from his own fight on the frontlines to reveal it was he who put her up for the job. Michael urges her to escape the life of conformity she's chosen and instead live the life of adventure he knows she's always wanted. Tragically, it takes his own deal in the war just before her intended wedding to convince Peggy that Michael was right all along.

Tragedy is the watchword for Whitney/Agnes' story as well. When uncle landlord finds a younger piece to warm his bed, he throws the Cully women out of his home. And while the teenage Agnes continues to judge her mother harshly for ever submitting to the creep's advances, mom has a few harsh lessons yet to teach. No, Agnes won't be accepted into a prestigious college science program. No, women in their time and place don't get to make their own destinies. No, the feeling of being right is rarely a comfort against the oppression of sexism. Agnes' story ends with a moment presaged by Peggy and Sousa's own investigation into Whitney's past - the moment one became the other after the scientist with the starlet's face was discovered by a Hollywood agent. Broke and looking to any escape she can from life in Broxton, the young Frostling does for the porn-stached agent creepo what she never could for her mother's lusty beau: she smiles a pretty smile.

The two stories are highly instructive not just for what they tell us about who these women were on their own but for who they become as opposing forces. Peg's formative lesson was that she could only be great by being her one true self -to hell with the pushback she'd get from all corners for being "an independent thinker." Agnes learned that to get what she want, she had to become whatever men told her she should be. Let them change your name, your looks, your body. If you're compliant enough, you might eventually get what you want. One of those stories is inspiring. The other sympathetic if stomach-turning. That's the stuff great superhero/supervillain pairings are made of, and it's a solid philosophical divide to implant in our leads before the ladies eventually meet and clash over whatever Zero Matter will prove to be by season's end.