A tree that doubles as a rocket ship. Aristocratic villains in 18th-century military dress with televisions for heads. A hairless cat who growls "LYING" at any knowingly untrue statement. A planet-sized bordello hosted by a pair of women's heads on fishnet-stocking-wearing legs.

This is but a dash of the unbelievable imagery you encounter in just the first six issues of Saga, Brian K. Vaughan and Fiona Staples's epic, dizzyingly original space opera published by Image Comics. The hardcover collection of the first 18 issues, in stores today, is not just one of the standout comic books of the last decade. It's an incredible affirmation that there's still room for originality in science fiction, even in a marketplace dominated by powerhouse franchises.

The space opera—a sub-genre of science fiction that tends towards vivid, romantic fantasy and swashbuckling action and away from "harder," more speculative sci-fi—has never really gone fully out of vogue since the success of Star Wars. But it's gotten pretty stagnant, recycling the most universally recognizable tropes. Find me a sci-fi action adventure that doesn't have "a Han Solo" or a damsel in distress—they're few and far between. Even J.J. Abrams's (largely successful) reboot of the Star Trek franchise drew heavily from George Lucas's favorite motifs. What Saga is doing feels different and invigorating. It's inspired by a fictional universe Vaughan created as a child and never stopped revisiting, and its core elements have the kind of loopy, fearless freshness only a young mind could generate.

I'll try to summarize the plot as cleanly as possible. Saga is set in a galaxy in an eternal war with itself, with every planet and species allied to either the winged people of Landfall or the magic-using folk of its moon, Wreath. Our heroes are a pair of soldiers from the warring races who have conceived a child against all odds—and that child serves as our narrator, telling the story of her parents and her upbringing as they hop across the stars to avoid assassins, armies, and bitter ex-lovers. One of their chief pursuers is a hitman called The Will, who is always accompanied by his Lying Cat.

One of the best arguments in favor of reading Saga is that it's practically unfilmable. "I don't think the technology or financial model exists yet to realistically make Saga work as either a television series or a feature," Vaughan said in an interview with Comic Book Resources. He allowed that he's happy to be proven wrong—"especially if Paul Thomas Anderson is looking to adapt a pervy space fantasy for his next project"—but his main point is the most crucial. Vaughan is using the serialized format of comics and Fiona Staples's terrific widescreen art to do things the Hollywood structure simply couldn't allow.

We're a long way removed from 1977. The bonkers chance 20th Century Fox took on Star Wars—which took place in a vast, complicated, original sci-fi universe—would be near-impossible to accomplish these days without using some established property as collateral. Forget Saga's occasionally visceral violence or sexual frankness; it's basically impossible to launch anything this ambitious in a global studio system. Guardians of the Galaxy was applauded this year for its inventiveness, but it was shepherded to screens under the hugely popular Marvel brand and quite rigidly adhered to its storytelling formulas. Twenty-four issues in (and with no sign of slowing down), Saga still manages to zig most times you think it'll zag.

It doesn't lack for dense mythology—if I sat someone down and tried to explain all the plot and character intricacies Vaughan has introduced, their eyes would likely glaze over. But it has the brilliant hook of the flawed, funny, deeply human couple at its center. In issue one, we're plunked into the middle of the action, centuries in to a galaxy-spanning war our narrator admits is futile to try and explain. But we immediately get that they're sick of fighting, that their inter-species relationship is generally considered taboo, and that they have a baby to protect. Every new detail and character Vaughan adds in provides a fascinating new wrinkle, but he's never dropped the core concept—that we're watching a couple in love learn how to be parents.

Fiona Staples/Image Comics

Saga also has the advantage of not being beholden to the machinations of a larger universe, something most mainstream comics have to contend with. A Marvel writer telling a specific story about Captain America might have to check with several other parallel comic book titles to make sure nothing contradictory is happening. DC and Marvel's publishing follows a set pattern of crossover "events" that get all the big characters involved in some world-shaking battle that are meticulously plotted out months in advance. Saga can take a left turn at any point without capsizing the ship. What seems like a one-issue side-plot, like The Will sojourning to a brothel planet, becomes almost as important as the main plot as he seeks to liberate a child prostitute he finds enslaved there. The bizarre internal logic of the Robot Kingdom, aristocratic soldiers with vintage TV heads who are all named "Robot," unfolds further each issue with captivating nuance.

There are plenty of other "creator-owned" comics (which tend to publish to independent labels like Image that grant authors total control of their work) that avoid the storytelling constraints of mainstream comics. But few combine Saga's epic scope with heartbreaking intimacy. Vaughan has long been one of comics' most innovative creators—his Y: The Last Man, Runaways and Ex Machina are all worth reading—but in Saga he's done more than create a brilliant comic. He's somehow managed to break new ground in a hoary old drama without feeling derivative. As I contemplate the never-ending barrage of cross-platform franchises in our future, Saga seems all the more necessary.