Movie Summary

John Wick loses his wife Helen to a terminal illness. Struggling to cope with her loss, he receives a beagle puppy named Daisy from her that she arranged to send before she died, to help him cope with his grief. At a gas station, he encounters a trio of Russian gangsters whose leader Iosef insists on buying his car, which John refuses to sell. That evening the gangsters break into John's home, knock him unconscious, steal his ca,and kill Daisy. Iosef takes the Mustang to a chop shop to have the VIN changed. Aurelio, the shop's owner, after recognising the car and deducing who it was stolen from, punches Iosef and throws him out. Aurelio is visited by John, who identifies Iosef as the son of Viggo Tarasov, the head of the Russian crime syndicate in New York City. Aurelio relays Iosef's activities to Viggo, who beats and berates Iosef before explaining to him who John Wick is: a famed assassin, formerly in Viggo's employ, nicknamed "Baba Yaga". When John wanted to retire and marry Helen, Viggo gave him an "impossible task," implied to involve multiple high level assassinations in a short period of time. John succeeded, and his efforts were key in establishing the Tarasov syndicate. Viggo tries to talk John out of seeking retribution, but John refuses even to talk. Viggo sends a team of hitmen to John's house, but John kills all of them.

Unsurprised, Viggo places a $2 million bounty on John's head and personally offers the contract to John's mentor, Marcus, who accepts. John seeks assistance from the New York Continental Hotel, which caters exclusively to the criminal underworld and permits no assassinations (termed "business" in their language) on its premises. Viggo doubles the bounty for those willing to break this rule to kill John. Winston, the Continental's manager, informs John that Viggo has Iosef under guard at his nightclub, the Red Circle. John enters the Red Circle and kills a horde of thugs to reach Iosef, who narrowly escapes after Viggo's lieutenant Kirill waylays and incapacitates John. John retreats to the Continental to have his injuries treated. Ms. Perkins, an assassin and former acquaintance, sneaks into John's room to kill him. Marcus alerts John, allowing him to subdue Perkins, who is forced to reveal the location of Viggo's front. He knocks her unconscious and leaves her with Harry, a fellow assassin, to await punishment, but she frees herself and kills Harry. John travels to a church in Little Russia which serves as Viggo's front and destroys his cache of money and blackmail material. When Viggo and his henchmen arrive, John ambushes them, but he is subdued and captured. Viggo taunts John for thinking he would be able to leave his old life behind. Before John can be killed, Marcus intervenes again, allowing John to free himself, strangle Kirill to death, and accost Viggo, who reveals Iosef's location.

Perkins learns that John and Marcus have been in contact and informs Viggo, who has Marcus beaten and tortured before executing him in his home. Viggo calls John to report this, planning to have Perkins ambush him. While waiting for John, Perkins is summoned to a meeting with Winston, who orders her executed for killing Harry on Continental grounds. Winston calls John to inform him that Viggo is planning to escape by helicopter. John races to New York Harbor, where he kills Viggo's remaining henchmen before fighting Viggo on the dock. Viggo pulls out a knife, and John allows himself to be stabbed, then disarms and fatally wounds Viggo and leaves him to die. John breaks into an animal clinic to treat his wounds and releases a pit bull puppy scheduled to be euthanized. John and the dog walk home along the boardwalk.