Nine years ago during the winter we find a small bank being robbed in rural Ludendorff, North Yankton. Three robbers - Michael, Trevor, and Brad - are busy taking the bank's assets. What should have been an easy hit turns into chaos as police forces attempt to stop them from leaving the area with the goods. A fourth robber driving the getaway vehicle is killed during the escape and the others find themselves in dire straits down the road after crashing at a farm. Although they lost the heat a sniper injures Brad and Michael while Trevor finds cover to take on the next wave of police. Trevor eventually flees into the snowy field leaving behind Michael and Brad. Sometime later at a graveyard a funeral is being held for Michael - although Michael is shown outside the fence looking on, and the sniper is among the mourners. iGTA5

Fast forward to present day Los Santos. Michael frequents a psychiatrist office to discuss his crumbling family. He is now in witness protection under the FIB who moved him and his family to LS under a sweet deal in exchange for his help in North Yankton. Outside the office he chats briefly with two young gangbangers named Franklin and Lamar who are looking for a house. These two repossess vehicles for a car dealer named Simeon Yetarian who uses shady business practices to ensure customers cannot keep up with payments. Although Franklin and Lamar are close to Simeon, their dreams of leaving the ghetto and street gang life drive them to begin stealing from him. During a routine repossession Franklin finds himself taking a car from Michael who has stowed away in the rear seat. Michael takes a liking to Franklin's do-what-I'm-told attitude and offers to have a drink in the future after Michael wrecks Simeon's business.

Now unemployed, Franklin takes up Michael on his offer of a drink. After saving Michael's son from trouble, Michael takes Franklin under his wing. One day Michael catches his wife's tennis coach with little clothing on and chases him to a Vinewood Hills home. With help from Franklin, Michael destroys half of the house and heads home only to find out the coach was actually hiding at the home of another client whose husband is a powerful gang leader named Martin Madrazo. He confronts Michael and makes sure the damage will be paid for. Michael contacts an old friend named Lester who sets up a heist at a jewelry store. Michael, Franklin, and others successfully make off with the jewels and lay low for a while.

Heading out to the deserts of Blaine County, Trevor is also still alive and a leading meth dealer at war against the Lost MC who inhabit neighboring areas. Trevor figures out that Michael was behind the jewelry heist and decides to travel to Los Santos to find his old pal who he thought was dead. Trevor has also been sending letters to Brad in prison. Before leaving for the city Trevor attempts to make friends with Chinese mobsters and eradicates the remaining Lost MC members as well as rival meth dealers named the O'Neils. Trevor leaves behind his right-hand man named Ron to oversee the business and takes with him a fearful follower named Wade who has a cousin Floyd in Los Santos. Trevor takes over the Floyd's apartment as his base of operations in the city.

Trevor reunites with a surprised Michael and the two attempt to catch up in-between the chaos of Michael's life. Family issues aside, Michael's exploits do not sit well with the FIB agents who gave Michael his deal and they force him to help cover their tracks as well as help the FIB against their rival government agency the IAA. Michael, Franklin, and eventually Trevor are brought in to help while keeping Michael's deal a secret. With his return to crime, Michael's family moves out for a while. Franklin continues to find more upscale criminal activities by doing extra work for Lester who needs high profile targets taken out. Funds acquired lead Franklin to residing in a Vinewood Hills mansion bought by Lester. A step closer to the high life but Franklin still finds himself involved with street gang hustling lead by Lamar. Meanwhile Trevor expands his business by stealing an experimental weapon from the government security contractor company Merryweather. All is well until Lester forces Trevor to return it before they all end up at the top of the kill list.