In the bustling city of New York, a calm summer day is shattered by a devastating explosion at the Bonwit Teller department store. The city is thrown into chaos when a mysterious terrorist calling himself "Simon" contacts the NYPD with a stern directive: he wants the recently suspended and alcoholic John McClane back on the force to play his twisted version of "Simon Says." Simon threatens to set off additional bombs throughout the city if his orders aren't adhered to, beginning a deadly game of wits with high stakes. McClane, burdened by his recent personal and professional troubles, is forced back into action.

As McClane steps into the dangerous game, he is unwillingly paired with Zeus Carver, a shop owner from Harlem who saves McClane from a potentially racially charged situation. Together, they race against the clock to solve Simon's riddles and prevent further destruction. It becomes clear that Simon's vendetta may have deeper roots, possibly connected to McClane's past encounters. The unlikely duo must navigate a labyrinth of clues and challenges, testing their resolve and uncovering the terrorist's true motives while trying to stay one step ahead of his lethal strategy. The city's resilience and the determination of these two very different men are put to the ultimate test.