The storyline in Grand Theft Auto III puts players behind Claude, a bank robber who is left for dead by his girlfriend and then quickly becomes caught in a world of gangs, crime and corruption.
In October 2001 in Liberty City, an ambitious criminal called Claude robs a bank with his Girlfriend, Catalina. The opening cutscene in the game shows them escaping from the Liberty Bank along with another male accomplice as well as a getaway driver called Miguel, showing outside the bank with a Banshee sports car. From the alleyway a gunshot is heard which indicated that the male accomplice has been shot. Claude then turns the corner to find Catalina pointing two pistols at him. She then tells him that she is ambitious and that he is just “small time”. She then shoots him and leaves him for dead. Catalina and Miguel then escape. Even though Claude survived from being shot, he was arrested and sentenced to 10 years in Liberty prison.
As he gets transported in a prison truck over the Callahan Bridge, the Colombian Cartel ambushes Claude’s police convoy for a prisoner, which ends up freeing Claude and a fellow prisoner, 8-ball in the process. Suddenly a dropped bomb on the bridge explodes which kills everyone but the duo and splits the Callahan Bridge into two, isolating Portland Island from the rest of the city.
8-Ball leads Claude to a safehouse and introduces him to the Leone mafia crime family; Sex Club 7 owner Luigi Goterelli, Salvatore Leone, the Don of the family, his Capo Toni Cipriani and the Don’s son Joey Leone. Whilst working for the family, Claude finds himself fighting the Colombians who are being led by Catalina in proliferating a new drug called “SPANK”. Meanwhile, Salvatore’s wife Maria, begins to take a liking to Claude. Salvatore doesn’t like the situation and leads Claude into a death trap, but Maria saves him just in time and they both flee to Staunton Island by a boat.
Claude then starts to work for the city’s Yakuza gang and its leader Asuka Kasen, Maria’s close friend who has Claude kill Salvatore and gets his revenge. This meant all of Claude’s ties with the Leone family have been cut off and they’re now against him. Claude’s work leads him to allying himself with other criminal sources, such as corrupt police detective, Ray Machowski, who is investigating SPANK and is an enemy of the Cartel. Claude later saves Ray from Internal Affairs and the CIA by helping him flee the city and Machowski escapes to Vice City.
Claude also meets Donald Love, a charismatic media mogul who maintains a huge media front, but to hide his secret cannibalism and necrophilia. In an effort to create a war between the Yakuza and Cartel, Claude and Donald Love organise the death of Asuka’s brother, Kenji Kasen and frame the Cartel. Later on, Donald asks Claude to rescue a man who was kidnapped by the Cartel in the prison truck in which Claude was in.
While Claude is on the job, he finally confronts Catalina face to face, but she eludes death and leaves Miguel to his fate, showing her cruel, violent and opportunistic side. Miguel is confronted by Asuka, who abducts him believing him to have knowledge of her brother’s death. Miguel then begs Claude to save him, but Claude leaves him after remembering his role in the betrayal. Soon after this, Donald disappears from Liberty City under unknown circumstances.
On the side, Claude also works for smaller street gangs, like the Diablos and their leader El Burro, Southside Hoods, the Yardies and serial killer / factory owner, Marty Chonks. The Yardies leader, the ambitious King Courtney, is responsible for Claude’s falling out with the Diablos and betrays Claude himself after allying himself with the Cartel. This leaves the Southside Hoods to be one of the few allies which Claude has.
With this war with the Cartel getting more intense, Asuka and Maria learn of Claudes’ history with Catalina and get him to fight many Cartel operations head on. Eventually, his exploits attract the attention of Catalina. This results in Maria’s abduction by the Cartel and the death of both Asuka and Miguel, killed by Catalina herself. The Colombian Cartel later demand that Claude is to give them $500,000 in exchange for Maria’s release. This gives Claude the opportunity to face Catalina once more.
When Claude makes it to the Cartel’s mansion with the money, he confronts Catalina who then attempts to get him killed there and then. Although he has his weapons taken away, Claude overpowers his would-be executioners and fights his way to the City’s Dam where Maria and Catalina are. In the resulting final firefight, Catalina attempts to flee the Dam in a chopper and makes a final attempt to end Claude’s life. Claude then proceeds to kill the remaining Cartel members holding Maria. He then gets access to a discarded rocket launcher and proceeds to shoot down the helicopter. He’s successful. He blows up the helicopter which effectively kills Catalina. As the game concludes, Claude and Maria leave the dam and Maria starts talking to Claude, before starting to complain about the state the kidnapping has left her in, such as the state of her clothes and nails, to the frustration of Claude. In the background, a news report can be heard about the recent events at the dam.
After the screen fades to black, a mysterious gunshot is heard and Maria’s voice is suddenly silenced, leaving it unknown if he killed her, or if Maria killed Claude.