SPOILER ALERT: If last week's episode of The Walking Dead is still sitting unwatched on your DVR, stop reading. Because we have to discuss the insane plot twists in the March 11 episode that left a nation of jaws unhinged. If you don't know the graphic novels The Walking Dead is based on, you like myself were most likely first overwhelmed by the realization that you can contract zombie-ism in ways other than a zombie bite. And then came the real shocker: the death of Shane Walsh (Jon Bernthal) and he's not the only major character on the show to die this season. (After Shane was killed, I kept telling myself that surely he would rise from the dead somehow and then he did!) Pound for pound and thrill for thrill, The Walking Dead could turn out to be the greatest thriller ever produced for television. Shane's death didn't seem like a gimmick done just for shock value. The Walking Dead dispenses with characters because the fragility of life is central to the story and frankly, because it can. Why? The real star of The Walking Dead is its sharp, humane writing; writing so great it's never drowned out by the death-rattle grunts of roaming zombies or washed away on rivers of gore. Though The Walking Dead's ratings on AMC are gargantuan for basic cable (and would be quite respectable for a major network), the show remains a testament to the creativity forced on TV producers in recent years by the rise of a million cable channels, the fractured attention of the audience, and other seismic shifts in the industry. While fighting for the eyeballs of 18- to 49-year-olds, most of the networks have been swinging for the fences with delightful regularity. You saw the proof in the strong new shows last fall. You feel it every Sunday night when you're faced with hours of amazing programming. And you feel it now, on the eve of the return of AMC's breathtakingly smart Mad Men, and the second season of this week's cover subject HBO's epic, outrageous drama Game of Thrones. Of course, for every risky, visionary thing that works in Hollywood, there are dozens more that don't, which is why the movie industry feels so much better investing in well-known superheroes and sequels. Last weekend, while The Walking Dead was scaling new creative and dramatic heights on TV, Disney's expensive attempt to launch a new movie franchise, John Carter, fell flat at the box office. There's a vast difference in the artistic merits of The Walking Dead and John Carter, but I give them both points for trying to give us something new. I would rather be befuddled by an ambitious failure than placated by a safe bet.