As "Agent Carter's" accelerated sophomore season continues to kick out double shots of episodes on ABC, the Marvel TV period piece has benefitted from getting the ups and downs of its story in front of fans as quickly as possible. Overall, this season has remained a smart, breezy ride much like its initial one. But as the episodes have pushed closer and closer to the endgame, the show's proclivity towards holding back its payoff until the bitter end could have wore thin. Luckily, tonight's one-two punch of "The Edge of Mystery" and "A Little Song And Dance" provided an hour of perfunctory setup and an hour of bonkers pop performance that dazzled rather than dragged out over multiple weeks.

The first episode of the pair presents the classic "calm before the storm" moment that's as much a part of the playbook for a comic book show as secret identities or action-packed car chases. Throughout the hour, we check in on each corner of Peggy Carter's universe as the plot ticks slowly towards a final confrontation.

We open by pulling the heartstrings as the Jarvises work their way through Anna's shooing last week. Edwin stands by a watchful wreck as his post-surgery wife remains in a coma. It's standard anguished husband material as Edwin makes a list of increasingly serious, always sincere marital promises if she'll only come back to him. The material itself is unmemorable, but the producers bank on the fact that the pair's intense likability will invest the audience fully in the moment. And if that doesn't work, there's always the hidden secret that Anna is now incapable of having children to add instant sympathy to the mix. Your mileage, as they say, may vary.

Meanwhile, Carter herself and Chief Sousa dedicate themselves to freeing the Zero Matter-infected Dr. Wilkes from the Zero Matter-obsessed Whitney Frost. Of course, our agents have no idea that Frost is slowly driving Wilkes into the hunger for power that has driven her mad, and their investigation drags a bit as the pair rough up Frost's manic mob boss sweetie. But their quest to create fake uranium to trade for the doctor's life is really just a thread to underscore the love triangle that has improbably become the beating heart of this season. Once Wilkes turns on his friends in order to secure the uranium, the ensuing standoff becomes a referendum on how Peggy feels about Sousa. The tension is leaden, but to the show's credit it's not obvious which man the audience "should" be rooting for. In an era where "will they/won't they" is often replaced by "when will they because you know they're going to," a legitimate triangle is impressive in and of itself.

Lurking on the outskirts of the plot is Jack Thompson, working hard to earn his status as the show's go-to shitheel. After leaning hard on one of his war drinking buddies for a supposed bombshell file on Peggy's past, Thompson begins to have doubts about his hero worship of Grade A scumbag Vernon Masters. It doesn't hurt things that Peggy's convinced the file is worthless. But even when confronted with the idea that the truth of the report is irrelevant to its ability to ruin Peg's career, Thompson sneaks behind his boss' back -not quick enough to stop the man from stealing the uranium from the SSR but at least learning the location of Frost's test site in the process.

Everything comes to a head when the SSR team heads out to the desert to stop Frost's plan with second-string comic relief/Howard Stark fill-in Dr. Samberly in tow along with a Stark designed "Gamma Cannon" (perhaps the easiest Marvel U reference imaginable) to stop the creation of more Zero Matter. So of course it all goes wrong. When Frost's bomb goes off, the result ZM cloud draws Wilkes into its embrace. The Gamma Cannon goes off in time to stop its spread and deliver a comatose doctor back to the dirt. Frost is enraged at being passed over by the mysterious force that may or may not exist on the other side of that cosmic divide, but at least she can bounce back easily from a pair of kill shots delivered by an unhinged Edwin Jarvis.

Ultimately, part one of this adventure ends with a classic cliffhanger and a classic lack of resolution. Anna Jarvis is unavenged. Neither Frost's side nor Peggy's is able to accomplish what they want. And our heroes are in as screwed a spot as they've been all season - Peg and Jarvis in Frost's hands and the trio of SSR men stranded in the desert. It's remarkably frozen in place for an hour of action, but at least it promises that the real ending can't be much further off.

The second half of the adventure ratchets up the stakes and the payoff in as many ways as a penultimate season episode can - starting with a bonafide Hollywood musical number starring the vast majority of this season's cast and a few extra faces thrown in. It seems an odd creative choice from the outside. Peggy daydreaming of a "Wizard of Oz"-like transformation that goes from black-and-white banality to Technicolor craziness while laying unconscious in the back of a truck feels a bit out of place even for this show. But by starting the sequence with her long dead brother Matthew, the reasoning for the production and its timing come into focus.

As Matthew reminds Peg and the viewer, her life in the SSR is nothing less than her own single-minded pursuit of the kind of life she's always wanted. And so the question for the character and the season becomes, "Which of the men in Peggy's life represent that life best?" As she swings and sings her way through a barrage of dancers (including the sadly absent from this season supporting player Angie), Peggy is faced with both of her smiling suitors and seems legitimately unsure of who she should choose before a top-hatted Jarvis wakes her up to reality.

This is the kind of flashy, water-cooler moment that network show used to drop into the mix during sweeps week in order to boost audience interest and goose ratings. That it falls in the 10 o'clock hour of a two-part burnoff of episodes says a bit about how much ABC is supporting this series, but while it may fail as a marketing gimmick, the number succeeds in finding a new way to play the idea of a love triangle that's entertaining, quick and memorable. And that the hour doesn't spend the rest of its time dwelling on that triangle is a godsend -both because the idea of turning this show into a romantic comedy sounds awful and because the characters have much bigger fish to fry.

Back in reality, all of our characters jump back into action with a number of ticking clocks hanging over them. Dr. Wilkes is almost ready to burst with the Zero Matter that he picked up on the other side of reality (another side that apparently had no choirs of angels or otherwise intelligent life to guide him), and Frost is desperate to pull it out of him. Peg and Jarvis are under the gun to escape from the back of Frost's truck and then push forward in stopping her before she gets what she wants or worse. Sousa, Thompson and Samberly are picked up by a pair of crooked agents under the thumb of Masters, and they have to think quickly in order to avoid a desert execution to say nothing of turning the tables on the corrupt superior.

Within that framework, the hour delivers up a number of cracking scenes on its way to finally letting the sci-fi conceit of the season have an impact of some kind. First and foremost is Agent Carter's tough love moment with Jarvis. Though he left his wife last episode thinking he'd avenge her attack or (more likely) die trying, the show's upbeat butler now stands defeated emotionally. Robbed of his revenge or a sense of where to go from here, he lashes out at his one friend in the mix, and Peggy ain't having any of it. With a monologue that could easily be described as ruthless, Peg confronts Edwin with the reality that he's blaming everyone for his wife's wounds but himself when he more than willingly threw himself into every dangerous situation we've seen for two seasons. The rough Carter seems ready to dump their partnership forever in the face of a whiner who's not lost nearly as much as she has (props to the series for not tossing in a Steve Rogers reference here when we know who she's thinking of already), but Jarvis' last minute reveal of his wife's true loss brings the pair back together for the mission moving forward. Its an expected moment but one the actors pull off with aplomb (though it's hard to shake the finality of Peggy's previous statements).

On the other side of the coin, every weird, winning moment of the SSR story came at the hands of Jack Thompson. From the second he convinces Masters' goons to not only keep him alive but Sousa and Samberly too, the audience is made to wonder exactly which master the smarmy chief is serving. While all the in between moments tell us that Jack is back on the side of the angels, his actions always seem to indicate that he's looking out for #1 by slugging Sousa or simply taking charge of the case against Frost that's been Peggy's game all season long. When he finally turns over his cards all the way, we see that Thompson is both serving himself and the greater good by sacrificing Masters, Wilkes and every villain in one massive bomb plot. It's the kind of plan that is admirable but not 100% heroic - the kind of semi-heel turn that makes the show feel chaotic in the best way.

As Thompson's scheme comes into light, the other fireworks from the episode come with Peggy's most bad ass performance of the season. Song-and-dance number aside, Peg's focus has been nowhere near her love life. She punches out Masters on her way to defending her friends and breaks the arms of any number of mob goofuses on her way to saving Wilkes before Thompson's bomb can go off. This is why we watch this show - to see a woman in full control of her own action hero abilities and with little worry for anything aside from saving the world. It's just enough of a refocus to make up for the slightly winding path the story took this season, but it's still not enough to close things out entirely.

When all points converge on the sewage plant where Frost has been vainly trying to suck the Zero Matter from the unstable Wilkes, very little is under control. Wilkes himself turns Peggy away from his volatile physical state and his volatile personality. Thompson angrily asserts the necessity on his doublecross even as Sousa and Samberly attempt to jam the signal that will set his bomb off. And in the final moments of the episode, Frost herself appears ready to be eaten in the black burst of energy that emanates from the tortured doc's chest.

And where does that leave us? Well, if you watched beyond the fade-to-black cliffhanger and into next week's preview, you know that Whitney Frost will survive, but beyond that, nothing much is known about how the season will end. Will Peggy have to choose between her suitors or even have the chance to choose poor Wilkes? With the SSR survive the fallout of Thompson's lone wolf status? Will Frost ever transform into the Madame Masque character who has one of the all-time great Marvel Comics visuals (thanks, Gene Colon)? And what will all of this have to say about the future of this series and its hero? See you next week to find out!