John Wick is making his way through Manhattan before he is labeled "excommunicado" as a result of his murder of Santino D'Antonio on Continental grounds. He heads to the New York Public Library to get a marker medallion and a rosary, but is injured in a fight with another hitman named Ernest on his way out. He then seeks medical attention from an underworld doctor. Before he can finish, the excommunicado status activates and John is forced to finish the suturing himself. As he leaves, he is pursued by wave of assassins, but he is able to kill them all before escaping.
John meets with the Director, the head of the Ruska Roma crime syndicate, presenting her with the rosary to receive safe passage to Casablanca. The Director allows it as John was once a member of her organization. Meanwhile, an Adjudicator from the High Table is sent to meet with Continental manager Winston and the Bowery King and tell them that they have seven days to resign from their positions for helping John. They later hire Zero, a Japanese assassin, who orders him to stab the Director through her hands as penance. Once arriving in Casablanca, John meets with Sofia, an old friend of his.
John presents her the medallion, and Sofia returns a debt of John placing her daughter in hiding. John tells her that he must meet with the Elder, the person above the High Table. The two meet with her former boss, Berrada, who tells him the Elder can be found by wandering through the desert until he is no longer able to walk. When Sofia refuses to give one of her Belgian Malinois to Berrada, he shoots the dog only to find the dog was wearing a bulletproof vest. John prevents Sofia from killing Berrada, and the two fight their way out of the kasbah and drive to the desert, where Sofia drops John off. Seven days later, the Adjudicator and Zero confront the Bowery King, who refuses to relinquish his position. In retaliation, Zero's students slaughter most of his men before slashing the King seven times. Back in the desert, John collapses from exhaustion before he is brought before the Elder. who tasks him with killing Winston before he can forgive John. John severs his ring finger to prove his fealty to the Elder and gives him his wedding ring.
Upon returning to New York, John is attacked by Zero and students before reaching the protection of the Continental. The Adjudicator arrives, but Winston too refuses to relinquish his position, and John refuses to go through with killing Winston. As a result, the Adjudicator declares the Continental to be "deconsecrated", allowing business to be conducted on Continental grounds. As the hotel comes under attack from both High Table assassins and Zero's students, Winston provides John with weapons to fight back. Killing many of the assassins, John is eventually ambushed by Zero's students, whom he defeats. He soon confronts Zero, whom he also manages to defeat after a lengthy showdown by stabbing him and leaving him to die. After the fight, Winston begins a parley with the Adjudicator.
When John arrives at the parley, Winston shoots him, causing him to fall off the roof of the hotel. Winston once again reassumes his position, while the injured John is brought before the Bowery King, who agree to join forces and get revenge on the High Table.
