During the formative years of modern science fiction, writers warned against the Grandfather Paradox, in which a time traveler might visit the past, kill his or her ancestors, and end up never being born. But perhaps what they were really warning against was time-travel fiction itself, with mind-bending ideas and thrilling twists that—upon more careful consideration—usually turned out to be full of logical loopholes.

As any practical-minded scientist or engineer will tell you, though, a working model does not have to be rigorously, logically perfect: it only has to be "good enough." Good enough when ignoring air resistance. Good enough for velocities much slower than the speed of light. And good enough to tell one of the most addictive sci-fi thrillers in recent anime history—which is exactly what Steins;Gate is.

One of the series' smartest moves is to mislead the viewer in the early going. Beginning with an obtuse pilot episode in classic "Nothing makes any sense" mode, it then segues into a ball of comedy fluff where wacky nerds do wacky nerdy things. Daru visits maid cafés and creeps on the ladies, Mayushii tries out some cosplay, and Okarin blurts out conspiratorial technobabble into his phone with no one on the other end of the line. Irritatingly clichéd behavior? A tongue-in-cheek poke at everything that's wrong with genre entertainment today? Or could it be that the show is actually endearing us to the characters, giving them quirks and qualities that end up being pivotal to the story?

As more characters join Okarin's group and more discoveries are made, the series tries its best to confront the "hard science" aspect of time travel, sometimes stumbling along the way. You can't time-shift objects with mass, so only electromagnetic waves work at first. Then they go from time-traveling text messages to time-traveling brain waves. A supposed time-traveler named for a turn-of-the-millennium urban legend shows up to prove it can be done. Oh, and at some point they acquire a retro computer so they can hack into the European research agency. But it is not until the halfway point that all this advanced physics chatter and magical hand-waving clears the way for a cliffhanger that turbo-charges the series into the thriller masterpiece that it is.

Admittedly, some might criticize Steins;Gate's second half for snowballing into an over-the-top genre patchwork—part Quantum Leap, part Groundhog Day, part Terminator, and quite frankly the only thing they're missing is a Delorean. Yet the fact that it pays homage to such predecessors is part of its charm. Just as the early episodes took a poke at the geekiest traits of late-night anime, the briskly paced, cliffhanger-laden endgame is a knowing nod to time-travel lore, able to stand tall because it rests on the shoulders of John Titor, Sarah Connor, maybe even the machinations of a certain Haruhi Suzumiya. By those final episodes, as Okarin races to undo the damage he's done, the puzzling events of Episode 1 loop back to provide a rock-solid climax, and the seemingly stereotyped characters are now beloved friends on an unforgettable (if sometimes logically shaky) adventure.

Character designs by huke of Black Rock Shooter fame also help to make the cast of Steins;Gate a memorable bunch. Apparently they all have several copies of the exact same outfit in their wardrobes, but it's hard to miss Okarin's trademark labcoat, Kurisu's blazer and tie, Mayushii's powder-blue ensemble, or even just Daru's extra-extra-large stature. (In a medium where seemingly everyone is a wispy schoolkid, simply having a fat guy as a main character is a breath of fresh air.) The backgrounds also have a distinctive touch to them, with languid midsummer haze and the bustle of Akihabara providing the setting for the series. The overall look leans a bit toward the gray, muted side, but still has enough splashes of color to be visually engaging. However, one area where the series skimps a bit is on animation, where frequent dialogue scenes provide an excuse to slow down the framerate and resort to canned "talking head" shots. Of course, the show still gets its fair share of action-packed camerawork—especially in the closing episodes—but activities like text-messaging the past are obviously meant more to tickle the brain than the eyes.

With so much already going on in the story, the series can afford to relax a bit on things like background music; a variety of light instrumental tracks sets the mood effectively even if nothing particularly stands out. One might even forgive the sentimental balladry in the last few episodes as the show tries to shoehorn a romantic subplot into the ending. The theme songs also fall on the ordinary side: a catchy rock opener and a more subdued closer, which eventually start to stick in one's head if only because of repeated listening every episode.

Perhaps Steins;Gate's most notable contribution to the time-travel genre is the way it winks and nods at everything that's come before. With an unapologetically geeky protagonist leading the way, this is a full-out love letter to that entire branch of science fiction—hard, and soft, and in between. Yet even with all the familiar plot elements and pop-cultural references, this is a story all its own, with likable characters that can't be found anywhere else and a number of wild, mind-bending twists that will leave viewers hooked. The visual style, while not the most striking or innovative, still has enough enough flair to be memorable. And as an overall package, well—by the time you get to Episode 24, you'll want to build a time machine just to go back and relive the thrill all over again.