The movie starts out with Smith's character, Robert Neville, roaring around Manhattan in a sweet car, hunting for food. The visual construction of a barren, silent New York City is this film's strength. It's eerie to see "the city that never sleeps" half-crumbled, overgrown with weeds and devoid of human life. We discover that three years earlier, a virus took hold of the city and wiped out the entire city's population (and then the world's population) — with the exception of a few immune people, like Robert, and a group of infecteds who turned into "the night seekers."
These former humans are now vampireish, zombielike monsters who can't stand the light and prowl around at night looking to destroy/infect any survivors. Robert, a scientist, diligently works to find a cure for the virus using his blood, though capturing an infected without being attacked himself proves challenging. Thus, it turns into a race against time: Robert trying to figure out a cure before any of the night-seekers destroy him.
The science-fiction aspects of the film are often intriguing — and far and away more interesting than the disgusting animated night-seekers who alternate between gratingly annoying and laughably ridiculous. The vicious, hairless, screeching monsters resemble larger and stronger versions of Gollum from Lord of the Rings but are emptier and more pointless versions of Gollum. As the film continues, there are more and more jump-scares, featuring a quiet scene jarringly interrupted by a sudden noise (usually the outrageously obnoxious monster screaming sound), a tactic that grows incredibly tiresome.
Soon the struggle becomes that of Robert trying to stay alive against an army of night seekers — which, while more action-packed, is a far less compelling storyline than seeing Robert figure out a cure. Thus, there are ways that this movie could have been cooler and more interesting, but the cheap scares and goofy CGI monsters bring it down many notches from what it might have been.