MrBeast challenges a random person named Alex to survive in a grocery store, offering $10,000 for each day he stays. The catch is that Alex has to "pay" MrBeast back $10,000 worth of groceries each day to receive his winnings, leading him to strategically sell off items like electronics, dog food, and eventually even the water he used for his shelter. Alex builds makeshift living quarters, including a shower and bed, and even gets a forklift to help move items. The challenge gets harder when the power goes out, but Alex pushes through, eventually reaching day 45 and winning $450,000 before deciding to leave to be with his family.