A strange man (later introduced as Griffin) arrives in Iping and takes lodging at the Coach and Horses Inn. He is completely wrapped up in clothing, which he does not take off even after Mrs. Hall, who runs the inn, lights a fire for him. Mrs. Hall notices that Griffin’s face is also wrapped in bandages. Griffin is rude to her, and impatiently asks when he will be able to get his luggage from the train station. Later that day, Griffin explains that he is an “experimental investigator” and that he needs his equipment.
The following day, the carrier Fearenside brings Griffin’s luggage, which is filled with scientific equipment, handwritten notebooks, and crates of fluids, some of which are labeled Poison. Later that day, Mrs. Hall hears the sound of bottles smashing, and when she asks Griffin about this he tells her not to bother him, saying that she can add extra charges to his bill. Griffin stays at the inn for a number of months. He does not attend church or communicate with anyone outside of the village, and only goes out at night. The villagers gossip, inventing many different theories about him. The local doctor, Cuss, visits Griffin at the inn, and is shocked to see that his sleeve is completely empty where an arm should be—yet he still manages to pinch Cuss’s nose.
On the holiday of Whit Monday, Rev. Bunting and Mrs. Bunting wake up to sounds of the vicarage being burgled. They try to catch the robber, but cannot see anyone there. The same morning, Mr. Hall and Mrs. Hall notice that the door to Griffin’s room is open, and his bed is empty. They call Sandy Wadgers, the blacksmith, to change the locks so they can lock Griffin out, but while they are discussing this Griffin emerges from his room (though it had seemed empty before) and goes into the parlor, which he has been using as a personal study. He locks himself in and can be heard shouting and smashing things. Later, Mrs. Hall asks Griffin why he hasn’t paid his bill; when he offers her money, she is suspicious, as just days before he said he didn’t have anything.
When confronted by the villagers at the inn, Griffin takes off his bandages to reveal a “black cavity”—his invisible face. On learning the truth about Griffin, the villagers flee in horror. The local constable, Bobby Jaffers, attempts to arrest Griffin for burgling the vicarage, but fails and Griffin escapes.
Outside of Iping, Griffin seeks the help of a local “tramp,” Thomas Marvel. At first Marvel thinks he’s hallucinating when he hears a disembodied voice talking to him, but Griffin proves that he is real and invisible by throwing stones at him. Amazed, Marvel agrees to help Griffin, and returns to the Coach and Horses, where he seizes some of Griffin’s belongings from his room, including his notebooks. Dr. Cuss and Rev. Bunting had previously looked through the notebooks while Griffin was gone, but couldn’t understand their contents. Mr. Huxter attempts to catch Marvel but fails. Griffin smashes the windows of the inn and cuts the village’s telegraph wire before fleeing. Everyone in Iping is too scared to come out of their houses for two hours.
Marvel tries to quit his role as Griffin’s helper, but Griffin threatens to kill him if he betrays him. The next day, Marvel and Griffin reach the town of Port Stowe, and Marvel strikes up a conversation with a local mariner. The mariner tells him the rumors about the Invisible Man and shows him a newspaper article about the events in Iping. Marvel boasts that he knows about the Invisible Man from “private sources,” but after Griffin hurts him he goes back on his word and tells the mariner that the whole story is a hoax.
The narrative shifts to a man named Doctor Kemp as he sits in his office, which overlooks the town of Port Burdock. He is dismayed by local gossip about the Invisible Man and the “fools” who believe the story is real. Nearby, Marvel bursts into the Jolly Cricketers pub, explaining in terror that he needs help because the Invisible Man is after him. Griffin enters the pub too and there is a scuffle. One of the men in the pub shoots the air, attempting to hit Griffin.
Doctor Kemp’s doorbell rings, but his servant tells him that no one was there when she answered. Kemp then finds blood on his bedroom door handle and floor. In his bedroom, Griffin speaks to Kemp, and at first Kemp refuses to believe that he is really there. Griffin introduces himself, reminding Kemp that they studied together at University College London. Kemp eventually believes Griffin and gives him food and whiskey. He allows Griffin to sleep in his bedroom, and when he goes to sleep worries that Griffin might be insane and “homicidal.”
The next day, Griffin tells Kemp that years earlier, while researching light and optics, he discovered a way of turning living tissue invisible. He kept his findings to himself, worried that someone would steal them. After spending three years researching invisibility, Griffin realized that he would need money in order to actually conduct the experiment. He stole money from his father that did not actually belong to him, which led his father to shoot himself. Griffin admits that he did not feel guilt or sympathy for his father.
Griffin says he first tested his invisibility experiment on a piece of fabric, and then on his neighbor’s cat. The cat’s pained meowing awoke his landlord, who grew suspicious of Griffin’s activities. Griffin then conducted the experiment on himself, successfully turning himself invisible. Aware of his landlord’s suspicions, he set his apartment on fire and fled. Out in the world, Griffin found it harder than he assumed to be invisible. He regularly bumped into people, was freezing because he could not wear clothes without being seen, and couldn’t eat, as food showed up in his stomach before it was fully digested. He robbed two different stores, but each time got perilously close to being discovered. He was eventually able to rob clothing and other items to disguise himself, wrapping himself up to conceal his invisibility from the world. He eventually traveled to Iping, hoping to continue his scientific research there.
Griffin tells Kemp that he plans to impose a “Reign of Terror,” killing people as he sees fit, in order to institute “the Epoch of the Invisible Man.” He hopes that Kemp will work with him, but Kemp warns him that he is choosing the wrong path. Colonel Adye then arrives at Kemp’s house, and on hearing this, Griffin shouts “Traitor!” and flees. Adye and Kemp warn everyone in the local area about Griffin’s plans, and a manhunt begins. Mr. Wicksteed, the steward to Lord Burdock, is found murdered on the grounds of Lord Burdock’s house. No one knows exactly what happened, but everyone agrees Griffin is responsible.
Griffin attacks Kemp and Adye at Kemp’s house, shooting Adye with his own gun. Kemp flees, begging for help from his neighbor Mr. Heelas, who refuses. Kemp runs into town being chased by Griffin. A mob of people descends on Griffin, and although Kemp begs them to have mercy, Griffin is beaten to death. His body becomes visible again as he dies.
In the epilogue, the narrator explains that after Griffin’s death, Marvel used the money he stole from him to become a landlord. He is now a respected man in the local area who has a “reputation for wisdom.” Sometimes Marvel shares his stories of the Invisible Man with passersby. However, he never reveals that he kept Griffin’s notebooks, which he keeps stored secretly and whose contents he does not understand.