According to 2004 estimates from the American Cancer Society, 10.3 million U.S. citizens are living with cancer. Advances in science have greatly increased chances of survival of those in that number; still, the mere thought of having any form of the disease is an internal struggle you wouldn’t wish upon your worst enemy. For many, word of the affliction’s demise cannot come soon enough.

I Am Legend opens with a doctor coming on the nightly news with a hopeful declaration that the said millions of affected have waited to hear: “We have cured cancer.” More catastrophic words have never been uttered. This so-called cure ultimately proves to be an unrelenting, incurable virus that kills 5.4 billion people, essentially wiping out the planet. Of the 600 million people left, 588 million transform into hideous, vampire-like beings that resemble the second cousins to the creatures that lurked in the caves of The Descent. There’s good news and bad news for the remaining 12 million. The good: They are completely immune to the virus. The bad: With McDonald’s and Subway shut down, they also happen to be the primary food option on Earth.

The agile monsters get their pale hands on everything breathing, save for decorated military man Dr. Robert Neville (Will Smith). You’ve heard the old saying, “No man is an island.” That doesn’t apply in the year 2012. Neville has Manhattan to himself. Deer run wild through Times Square. Weeds sprout through Big Apple streets as if they always had. Every day Neville goes to the same spot at a pier, anxiously waiting for another human to arrive. The Brooklyn Bridge, or what’s left of it, dangles off in the distance. Here you’ll want to close your jaw before drool starts dribbling from it.

But how Legend becomes more than just a collection of how’d-they-do-that visual moments is with the philosophical questions presented. Really, no matter how steadfast you might be to finding a vaccine like Dr. Neville is, could you honestly go on not knowing if you’d ever see another human being again? If your child (in this case, Will’s own daughter, Willow) and wife (Salli Richardson) are dead, what would possibly be your motivation to continue on? F*ck vampires. That thought alone is scary as hell!

Director Francis Lawrence (Constantine) addresses these questions earnestly. Smith, meanwhile, juggles the determined doctor and losing-it loner dynamic brilliantly. You’re watching Castaway, only with skyscrapers and bloodsuckers instead of sand and volleyballs. In fact, the only problem you’ll have with this 100-minute gut check is from a comprehensive aspect. With iPods blasting Bob Marley’s Legend and stovetops cooking eggs, you’re irked that the source of the utilities is never really explained. But because Lawrence and Smith make such a believable team here, that comes off nitpicky in the grand scope.

Already a top-tier choice for humor movies, cop dramas and July 4 action flicks, with I Am Legend, Will proves he can conquer horror and most anything else in Hollywood, too. Could Smith’s cure for cancer be that far off?