5 Assassins Aboard A Bullet Train Try To Deceive & Kill Each Other

 Bullet Train opens at a hospital in Tokyo. Yuichi Kimura, aka ”The Father” is by the bedside of his son, Wataru, who has been pushed off a rooftop while his father was absent.

Yuichi’s father, “The Elder”, arrives and reminds his son that fathers are supposed to protect their families. Yuichi goes off to find whoever hurt his son. An assassin named Ladybug is returning to work after a leave of absence. He considers the name ironic, as he doesn’t believe he is lucky like ladybugs usually are. He is also filling in for another assassin, Carver, who is sick. Ladybug speaks to his handler, Maria Beetle, who assigns him to board a bullet train heading from Tokyo to Kyoto. His task is to recover a briefcase containing money with a train sticker on the handle. As he makes his way over, Ladybug gets bumped into by Yuichi, causing him to drop a key to a locker and his train ticket. Ladybug breaks into the locker to find firecrackers, sleeping powder, and a gun in there, but he declines to take it, despite Maria’s insistence.

Ladybug boards the train, but is quickly met by the conductor who tells him he has to get off at the first stop because he didn't have his ticket on him. Onboard the train is “twin” brother assassins, Tangerine and Lemon. They were sent by a crime boss known as “The White Death” to recover his son, as he is a junkie that can’t be trusted on his own. Lemon lives much of his philosophy based on “Thomas The Tank Engine”, and he relates certain people to characters from the show. Tangerine explains to Lemon how White Death was a Russian wanderer who ended up working as the right-hand man of a Yakuza boss named Minegishi after proving his worth until he ended up forming his own gang and betraying Minegishi and killing him. While keeping the Son company, the brothers argue about how many people they killed altogether on their last mission, (one was an innocent bystander in the wrong place at the wrong time).

Yuichi also boards the train after finding a lead on who pushed Wataru. But he gets tased by an assassin called “The Prince”, who poses as an innocent schoolgirl to throw people off to her true nature. When he wakes up, she tells him that she pushed Wataru to lure Yuichi to her. Prince tells him that she has a henchman at the hospital ready to kill Wataru if he doesn’t hear from her every 10 minutes. Ladybug recovers the briefcase surprisingly easily and fast and makes his way out as he walks by The Prince. But before he steps out, he is found by another assassin known as “The Wolf”.A flashback shows Wolf working his way up in the cartel under a boss called El Saguaro and then finding a wife. However, everyone at Wolf’s wedding was poisoned, including El Saguaro and Wolf’s wife. He believes Ladybug is responsible for their deaths, and he attempts to kill him, but Ladybug gets saved by his phone, which blocked the stab. The two fight in the bar car, with Ladybug trying to calm him down, and explain to him that he doesn't know him, but without success, as Wolf is determined to kill him. Wolf throws his knife which bounces off the briefcase and plunges right into his heart, killing him. Ladybug covers up Wolf’s wounds to make it look like he's sleeping, steals his phone, stashes the briefcase in a compartment, and calls Maria. She informs him that he was a cocktail waiter at Wolf’s wedding, and the tequila served there was spiked with poison from a boomslang snake, which congeals the blood and makes you bleed out of every orifice, and if no antidote is administered in 30 seconds you die.

A boomslang snake was stolen from a zoo in Tokyo and is actually on the train. Lemon and Tangerine go to fetch the briefcase and prepare to leave when they notice it's missing, and when they return to their seats they see the Son has also been poisoned to death. They cover his face up and clean the blood before going off to find whoever stole their briefcase. The Prince saw Ladybug earlier, so she gives the info to Tangerine. Meanwhile, Ladybug encounters Lemon in the quiet car and recognizes him from a job in Johannesburg. They fight and exchange blows with one another while trying to not alert the other passengers in the car. Ladybug tries to disarm Lemon and ultimately knocks him out with a laptop. He spikes his water bottle with sleeping powder, stashes his gun, and steals his phone. Ladybug: Hey, bro.Ladybug: Wanna make an easy 200 bucks? Passenger: Is this like a... sex thing? Ladybug: Nope.Passenger: Oh, okay. I was kidding. Passenger: Yeah, what's up? What do you need, bro? Ladybug switches clothes with another passenger and talks to Maria again. She tells him that another assassin, “The Hornet”, who came up with the boomslang poison during The Wolf's wedding is also on the train and he's the one that poisoned The White Death's son. Meanwhile, Tangerine gets off at the next stop briefly to meet with White Death’s goons to assure them that the job is going according to plan, while Lemon tries to make it seem like the Son is still alive. Prince goes to the bar car and finds the stashed briefcase in the compartment by pure "luck".She then tells Yuichi she wants his help in rigging the briefcase and giving it to White Death to kill him.

Prince also gives him a rigged gun to blow his head off when the trigger is pulled, because The White Death always executes assassins with their own weapon. Yuichi then gets a call from his father and he explains the situation to him and tells him he went after the person that pushed his grandson. The Elder also overhears Prince on the phone. Tangerine finds Ladybug by tracking the phone that he stole from Lemon earlier and fights him, believing that Ladybug poisoned White Death’s son. They exchange blows with one another until Ladybug opens an emergency door and causes the two to nearly fly out of the train before pulling themselves back in. They briefly call a truce when Tangerine gets a call from White Death to let him know that if they do not show up with the briefcase at the next stop, he will kill everyone on the train. The two attempt to fool White Death’s men by posing as brothers, since the goons don't actually know what Lemon looks like. And also use a different briefcase, but Ladybug accidentally opens it and blows their cover, forcing them to run back onto the train. Tangerine says he still needs a fall guy for the whole situation and Ladybug is his best option.

The train arrives at the next stop and Ladybug then kicks Tangerine off the train before it starts moving again, but he jumps back on it before it pulls away too fast. He manages to break the glass with his brass knuckles and boards the train again. Meanwhile, Lemon comes across Yuichi and Prince, with whom he drinks some of the spiked water. He quickly determines that both of them are not there for noble purposes and that they must be the ones that killed The Son. Lemon shoots Yuichi, but after stashing his body he finds the rigged gun in Prince's bag. Unfortunately, the effect of the powder takes effect and he ends up passing out. Prince shoots Lemon repeatedly in the chest and stashes him and Yuichi in the bathroom. Ladybug finds a phone ringing that belongs to Yuichi. He picks up and speaks with the Elder, giving him the location of the next stop of the train. He then runs into the Hornet, who was in disguise on the train as a costumed performer who injected & killed the White Death's son with the venom, before swapping clothes with the concession girl. She stole the boomslang snake from the zoo and uses its venom to kill her victims. Hornet poisoned everyone at Wolf’s wedding, as she was also there as a pastry chef. Ladybug fights Hornet, who is there to collect her promised payment for killing the Son, which is the money in the briefcase. She tries to stick him with a syringe containing the venom, but he takes a light jab while sticking her with the rest of it.

Hornet then attempts to administer the antivenom, but Ladybug takes it from her and uses it on himself first. He then watches her crawl away and dies as karma catches up with her. Tangerine finds Lemon’s body in the bathroom and tries to go after his killer. He talks to White Death again, who says that he bought every last ticket to Kyoto so they would be the only remaining few on the train. Tangerine then runs into Prince and is almost fooled by her until he sees that Lemon left a sticker of the character Diesel from “Thomas”, meaning he knew she was the villain. Before Tangerine can kill Prince, Ladybug finds him again and tries to stop him, which ends up with Tangerine getting shot in the neck, and bleeding out before he can warn Ladybug about Prince. Ladybug tries to get Prince off the train at the next stop, but she deliberately stalls him and fools him with her innocent act, forcing Ladybug to go back in. The Elder also boards the train, since he overheard Prince on the phone earlier when he talked with Yuichi and knew something was wrong.

He sits near Ladybug and Prince, until Ladybug tries to move to another seat, but gets bitten by the boomslang snake, prompting him to walk away screaming and shoveling the snake down the toilet. The Elder confronts Prince and steals her bag just as her phone rings. She never picks up, so her henchman gets ready to kill Wataru. However, The Elder prepared for this and had his own assassin posing as a nurse to protect his grandson. She kills Prince’s guy before he can ever touch Wataru. Horrified, Prince flees, and Ladybug returns. Ladybug is fine since he was administered the antivenom earlier from The Hornet. The Elder talks to him about how Ladybug thinks he is unlucky and leaves him with the belief that everything happens for a reason and that fate brought him here. He also tells the story of how he was Minegishi’s original confidant before White Death betrayed them, and he vowed to take revenge on White Death for killing his wife. He went into hiding, together with his son, and plotted revenge ever since. They find Yuichi still alive and suddenly, Lemon wakes up as well. He has survived the shots to the chest thanks to a bulletproof vest.

He sits solemnly by his brother's side. He honors him by giving him the Thomas sticker. He then becomes enraged and tries to go after Ladybug for killing his brother, but Yuichi and The Elder talk them out of it, as they will stand no chance alone when facing the White Death. The train arrives in Kyoto as White Death prepares to board. Prince confronts him, and it is revealed that they are father and daughter. She wanted to get his attention since he favored his son and never cared for her at all. She attempts to provoke him on purpose to get him to kill himself with the rigged gun, but he simply walks away from killing her. Ladybug gives himself up with the briefcase outside, The goons take the briefcase, as White Death explains that everyone on that train was there because he orchestrated it– he has wanted revenge for the death of his wife, who was killed in a car accident that was an assassination attempt on him. Lemon and Tangerine killed White Death’s men on a job in Bolivia, which made him travel there on short notice and not be in the car as planned. He also did not care for his son, as his wife’s attempt to bail him out again from his crimes led to her death. Hornet was lured there because she poisoned the surgeon that could have saved his wife’s life. Finally, he believes Ladybug is Carver, who orchestrated the assassination attempt. He was betting on all the assassins to kill each other. Ladybug tries to explain to White Death that he is not Carver, but before he can, the goons open the briefcase which explodes, just as Lemon gets the train running.

Ladybug runs back on and is chased by White Death and his goons. The Elder and Yuichi take out the goons that boarded the train just as White Death confronts The Elder. They draw their swords and start battling, while Ladybug and Lemon fend off the henchmen in the driver compartment, as the train speeds out of control and goes on the wrong track, hitting another stationary train. As they battle the henchmen, Ladybug attempts to hit the emergency brakes. Lemon ends up throwing himself and the last henchman out of the train as they pass over a bridge. Before White Death can kill The Elder, Ladybug hits the brakes, and Elder seizes an opportunity to impale his enemy close to death. The train then derails and crashes into a town. The men miraculously survive and exit the train, and White Death attempts to execute Ladybug, but he uses the rigged gun and blows his own head off. Prince then tries to finish off Ladybug and the Kimuras, but she gets run over by a tangerine truck. Maria then arrives in person to rescue Ladybug while he part with the Kimuras. He has embraced a positive outlook on life and believes he really is lucky…until a telephone pole comes crashing down onto Maria’s car, forcing them to walk.In the post-credit scene, we see that Lemon survived the fall off the train and hijacked the tangerine truck, which he used to run over Prince and avenge Tangerine.