In September 2012, Lieutenant Colonel Robert Neville, an accomplished military virologist portrayed by Will Smith, finds himself as the lone, healthy human in a decaying New York City. The tragedy began back in 2009, when a genetically engineered variant of the measles virus, initially developed by Dr. Alice Krippin (played by Emma Thompson) as a promising cancer cure, mutated into a deadly strain. This so-called miracle cure had shown remarkable results during trials, successfully treating over 10,000 patients, but things took a dire turn when the virulent form manifested symptoms similar to rabies, ultimately leading to a catastrophic death rate.
The devastating spread of the virus claimed 90% of humanity, transforming the surviving population into predatory beings known as Darkseekers. Neville experienced profound personal loss when his wife, Zoe (Salli Richardson), and daughter, Marley (Willow Smith), perished in a helicopter accident during a chaotic evacuation in December 2009. A collision with an infected helicopter robbed him of his family just as the virus began to spread through the air. In a desperate attempt to find a solution, Neville chose to remain in New York City, dedicating himself to scientific research to discover a cure.
As time passes, nature slowly reclaims the cityscape, transforming it from the bustling metropolis to a ghostly shell of its former self, with all bridges to the area destroyed. Neville's daily routine is fraught with danger, as he scours the remnants of Manhattan to forage for supplies and hunt for deer, using his swift red Mustang for high-speed chases. He meticulously avoids darkened spaces to stay safe from the lurking Darkseekers, ensuring he returns to his fortified apartment before nightfall. Within this stronghold, he barricades himself in, sleeping in his bathtub armed with a firearm as the haunting cries of the night echo through the city.
In the sanctity of his apartment laboratory, Neville experiments on infected rats, tirelessly searching for a serum that could reverse the infection's effects. Despite his efforts, many of the compounds lead to the rats' demise, but one day, he uncovers a promising serum that reduces aggression and restores pigmentation. This discovery pushes Neville to elevate his research to human trials, while he continues to broadcast hopeful messages to any remaining survivors, inviting them to gather at South Street SeaPort.
Neville's solitude is occasionally punctuated by his loyal companion, a German Shepherd named Samantha, and his interaction with a series of mannequins he humorously imagines as patrons of a video store. However, tension escalates when during a hunt, Sam chases a deer into an ominous building, revealing a hidden base of Darkseekers. They barely escape as the sun exterminates the attackers, but the encounter leaves Neville shaken.
Determined to test his serum on a captured infected woman, he endures a heart-pounding confrontation with an enraged mutated alpha male who seeks to rescue her. Unwilling to give up, Neville documents his research meticulously across multiple drives while battling the emotional scars of his isolation. Things turn tragic for him when Sam becomes infected during a fierce encounter with a pack of infected dogs, and despite Neville’s desperate attempt to save her using his serum, he must ultimately face the heart-wrenching decision to end her suffering.
Consumed by grief and anger, Neville retaliates against a group of infected at the waterfront, only to be overwhelmed and nearly killed. He is unexpectedly saved by a pair of immune survivors, one being Anna (played by Alice Braga) and a young boy named Ethan (Charlie Tahan), who were responding to his radio calls. They bring him to safety and inform him of their journey to a rumored survivors’ camp in Bethel, Vermont—a claim Neville is naturally skeptical about.
Tragedy strikes again when an attack by the alpha male ensues at Neville's home. As he battles to save Anna and Ethan during a siege from the infected, he discovers that his serum is indeed working on the captured woman. In a race against time, with danger closing in, he sacrifices himself to ensure Anna can take the valuable antidote to the survivor's camp, ultimately cementing his legacy as a symbol of hope in humanity's fight against despair. Anna later reflects on Neville's indelible mark on their world—his bravery and dedication immortalized in their ongoing struggle to survive.
