Streamlined, savvy, and spectacularly effective, Signature Theatre’s Assassins looks through a glass darkly at the United States and the monsters she sometimes creates—and what director Joe Calarco shows audiences in his funhouse mirror is themselves.

Almost literally, in fact: Stephen Sondheim’s antic vaudeville on the lives of our nation’s presidential assassins has always been interested in its subjects not as monsters but as Everymen undone—Everywomen, too, lest we neglect the Manson acolyte and the desperate housewife. And while too much detail would ruin the shiver and the shock of the image Calarco has conjured for the top of the show, let’s just say when that skewed American flag of a curtain gets whisked away, Signature’s staging confronts spectators with a disturbing, disorienting visual metaphor for the notion that the next Booth or Oswald or Hinckley might be sitting in a seat down front.

It’s appetizingly solid, this production, with a seductively smart concept—Calarco spins out the story not in the fairground shooting gallery specified in John Weidman’s book but in some twilight-zone Odeon where patrons are both a voyeuristic audience and the stars of an upcoming reality show, and where a motley clan of killers sit glued to the action, watching us watching them. A circus band oompahs its way through a lopsided, waltz-time reading of “Hail to the Chief,” and a sinister proprietor (the ideally cast Steve Tipton) smilingly croons a welcome to one and all. “Everybody’s got the right to be happy,” this seductive opportunist sings to a gathering that includes the notoriously unhappy John Hinckley and Squeaky Fromme, “Everybody’s got the right to be different…everybody’s got the right to their dreams,” so why not “aim for what you want a lot—everybody gets a shot!”

It’s a dark, cynical read on the promise of the American way, a rebuke to the hucksters and the Hiltons who sell us daily on the idea that success and singularity matter most—and in an era of epic political disenchantment, an age of hijacked process and unabashed cronyism and a staggering lack of official accountability, Calarco’s chillingly intimate take on Assassins smoothly suggests that plenty of “us,” driven by our discontents and our entitlements and the needy, greedy American Dream, might need only the slightest of pushes to go howling over the edge to join the show’s infamous “them.”

And oh, what a “them” Calarco has put together. The plum parts are those of John Wilkes Booth and Lee Harvey Oswald, around whom Sondheim and Weidman structure their curious, history-spanning revue—the notion being that Booth, the nation’s first presidential assassin (an actor who struck in a theater, yet) crossed a psychological line that later malcontents were quick to toe, while Oswald scarred the nation like no one since Lincoln’s killer. The two are played here with an aristocratic swagger and an appealing vulnerability, respectively, by Will Gartshore and Stephen Gregory Smith, and the scene that brings Booth and Oswald together late in the show absolutely qualifies as one of the evening’s hair-raising high points.

But there’s a gratifying sense of ensemble at work in the little theater on Four Mile Run, too: From the gentlemanly Charles Guiteau (Garfield’s assassin, played by Mika Duncan) to the haunted socialist Leon Czolgosz (Tally Sessions as McKinley’s murderer) to the profane, unkempt would-be Nixon-killer Sam Byk (Andy Brownstein), the assassins are a movingly tormented bunch, pursued by demons as diverse as economic desperation, hero-worship, and religious delusion. Assassins even makes it possible to empathize with Matt Conner’s sweet, hurt Hinckley, Peter Joshua’s furious Giuseppe Zangara (he tried to shoot FDR but accidentally shot Chicago mayor Anton Cermak), and the daffy, intense, tragic twosome of Lynnette “Squeaky” Fromme (Erin Driscoll) and Sara Jane Moore (Donna Migliaccio)—off-kilter creatures who thought a shot at Gerald Ford would win them some kind of love.

Not that the show, for all its attempts to understand the desperation and the damage in these wrecked lives, ever excuses the damage they did to the nation. The Balladeer, a kind of all-American figure who keeps shining the light of day into the dark narratives that unfold in the assassins’ songs, insists over and over again that “angry men don’t right the wrongs, and guns don’t write the rules.” And although the Balladeer’s eventual corruption suggests a certain pessimism about how often the nation fails its weakest (Smith plays him, too, so the Balladeer can morph into a suicidal Oswald after an angry, disaffected chorus of “Another National Anthem”), the spare and unsettled agony of “Something Just Broke,” a chorale for the American bystander that follows hard on that chilling climax in the Texas Book Depository, reasserts the notion that an assassination represents a failure, never a triumph or a vindication—that an assassin leaves a scar, not a mark, on the body politic.

Calarco’s design team (James Kronzer on sets, Anne Kennedy on costumes, Chris Lee on lights, Tony Angelini on sound) works expressive miracles within a concept that might have come off seeming like a straitjacket: A couple of deftly negotiated cues transform banked theater seats into the grandstand where Zangara takes his shot at FDR, and later an eloquently simple device conjures Oswald’s Dealy Plaza aerie literally out of the dark around the audience. (Breathtaking, that moment, and a little heartbreaking once you realize where it’s going.)

Calarco, meanwhile, demonstrates a genuine gift for steering his audience: An actor flourishes an umbrella at the end of one ensemble number, and the light hits it just so, and your eye inevitably goes there—just in time for that character to step up and anchor the next sequence. At one point, Calarco tricks patrons into applauding the hanging of an obviously sick man, and he forestalls applause at another big moment by putting theatergoers in the uncomfortable position of agreeing with…well, let’s not spoil it. Such tricks keep wrong-footing the audience, and by the time the reprise of that “Everybody’s got the right to be happy” sentiment rolls around, Calarco & Co. are prepared to slip in one last surprise blow, aimed once again at the place in the gut where the breath lives. It’s pretty staggering—“dreams” may be the last word in the show, but the stage picture Calarco arranges looks more like a Columbine-era nightmare—and somehow it seems exactly the right note to leave on.

A bloody murder and a hangman’s noose figure prominent-ly in the new musical at Round House Theatre, too, as you might guess from the title, but A Murder, A Mystery & A Marriage makes altogether more chipper work of them. Based on a recently unearthed Mark Twain yarn, Aaron Posner and James Sugg’s show follows the trials and tribulations of a sweet young Midwestern thing (Erin Weaver) and the swain (Ben Dibble) who pines for her down at the general store, while an overprotective dad (Anthony Lawton) and a grudge-bearing uncle (Thomas Adrian Simpson) plot to keep ’em apart. A Mysterious Stranger (Scott Greer) figures in the story, too, and if the bits about the pretend nobleman and the young lady with the inheritance seem a little familiar, well, it may be because this story never got published, but Twain did after all go on to write Huckleberry Finn.

Round House’s production, directed by Posner (a Folger Theatre favorite based at Philadelphia’s Arden Theatre Company), makes stylish if slight work of what’s ultimately a slender show—friendly, unassuming, and cozy as the lively, folky tunes it serves up. The cast couldn’t be more agreeable—Sherri L. Edelen seems to be having a particularly good time as the put-upon heroine’s plucky Ma, and she’s in terrific voice. And though things do look dire for a while there, it won’t be much of a surprise to hear that Twain’s townsfolk uncover the truth and marry off the right twosome in the end. If Assassins and Sondheim have proved that the American musical is an art form sturdy and rich enough to chart the darknesses and the disappointments that real-life stories too often end in, A Murder, A Mystery & A Marriage demonstrates that the optimist, escapist musical comedy may still have a little life left in it yet.CP