Team Bucciarati has acquired the key the Boss has instructed them to find in Pompeii. After having gathered and stitched back Abbacchio's hand with a zipper, they all depart inside their minivan to Naples' train station. On the way, Abbacchio reexamines the jewel inside the key inside of which are engraved further instructions to head to the 6th platform of the train station and take the earliest train to Venice. Meanwhile, Fugo is unwillingly mixed with Mista's attempt at sneaking a peek at Trish's cleavage. The car suddenly swerves and Fugo is thrown into Trish's chest, causing Mista to loudly beg for mercy and deeply embarrass Fugo in the process.
At the train station, the duo of assassins, Prosciutto and Pesci, find Bucciarati looking around on the platform. While Pesci expresses a wish to avenge his fallen comrades, Prosciutto chastises his junior for expressing empty threats. As they close in on Bucciarati, the latter is perplexed that no present lock fits the key but finally finds a turtle whose shell has a key-shaped hole. Taking the turtle with him, Bucciarati suddenly rushes inside the train to his companions. When Prosciutto and Pesci arrive at Bucciarati's supposed position, they cannot find their target. Indeed, the turtle named Coco Jumbo is a gift from the Boss, possessing a "room" inside of its shell that people can access, complete with chairs, a couch and even a fridge with drinks in it. The small turtle sneaks past the assassins into the driver's cabin.
Prosciutto is sure that the group is somehow still aboard the train and decides to stay aboard with Pesci. On Prosciutto's orders, Pesci summons his fishing rod Stand, Beach Boy. Launching the hook and line through the door of the driver's cabin, Pesci only senses two lifeforms and hooks the driver, forcing the door open. Seeing no one in the cabin, Prosciutto shifts his attention elsewhere but Pesci privately investigates further, sure about the second lifeform. Although he almost finds the turtle, Pesci sees dark fumes and realizes that Prosciutto has summoned his Stand The Grateful Dead to wreak havoc and force his targets in the open. Distracted, he leaves the cabin.
Inside the turtle, the group tries to kill time as best they can. Mista offers Narancia a drink, but he is seemingly unable to hear him. To the group's shock, Narancia has become extremely old, with all the ailments that come with it. To their horror, the heroes realize that everyone is becoming older, and it is revealed that the entire train is aging at a dramatic rate. Realizing that a new Stand User is attacking them, Bucciarati immediately sends Mista out to fight their unknown enemy but the barely conscious Giorno stops him from rushing. Despite the urgency, Giorno notices that some of them have remained relatively young and that the assassin must somehow discriminate between people as they want Trish alive. Deducing that the ability affects the most those with higher body temperature, the group sends Mista out with the two remaining ice cubes from the fridge.
Out of the turtle, Mista decides to activate the air conditioning to help his teammates. However, Pesci, who is munching on ice in the bar wagon has turned the button into a bait for Beach Boy, immediately sensing Mista punching the button. Pesci hooks Mista who realizes he has two enemies to fight.
Abbacchio mentioning he thought the key would be for a helicopter and that it will be dangerous to travel by train has been removed.
The message inscribed in Mr.President's key from the Boss to Bucciarati is now written in Italian.
Abbacchio reads this aloud, while in the manga the message was only shown.
Fugo wondering if Trish is really a stand user in his internal monologue has been cut.
Trish's nipple is no longer shown. Mista and Fugo become giddy when she simply adjusts herself and her top shifts.
Mista's description of how he and Fugo could be executed for peeking at Trish's chest has been cut.
The reason Fugo is propelled toward Trish is changed from the minivan suddenly stopping to it swerving.
Mista is now shown grabbing Fugo by the collar and pulling him away from Trish.
In contrast to the original manga, Prosciutto's initial appearance is no longer obscured by shadow, as he was shown earlier during Formaggio's flashback in Episode 10.
Prosciutto commenting that he'd rather end the fight before the train leaves in order to avoid buying tickets has been removed.
After Giorno tells Bucciarati that the train is about to depart, Bucciarati telling him to go on and guard Trish and Giorno wondering what's wrong with the key has been removed.
When Giorno suggests Bucciarati try the lock on the fire hydrant, Bucciarati saying he already did has been removed.
Bucciarati discovering Mr.President's ability by having his hand sucked into Coco Jumbo has been cut. Mr.President's ability is only revealed once Bucciarati's group is already inside the turtle, and demonstrated when Narancia is accidentally pulled out of the room and hits his head.
The scene showing the interior of the room has been moved from after Proscuitto and Pesci board the train to after Pesci hooks the engineer.
Proscuitto asking if Pesci knows what Bucciarati's team looks like and Pesci showing the photos that were given to him to identify them has been cut. Their argument originally lasts longer as well.
Proscuitto is shown looking under the cab's door. Originally he points at it.
Multiple parts from the scene inside Mr.President's room have been altered.
Mista no longer wonders where they are.
Fugo is standing near Mista and Giorno rather than between Narancia and Abbacchio.
The gang no longer opens the cabinet containing the TV and turn it on.
The brief reference to Captain Tsubasa from the original manga is removed because of this.
Bucciarati no longer acknowledges that the room has running electricity.
The cabinet that will be used as Baby Face's hiding spot is shown, in contrast to the original manga that didn't feature it before the corresponding arc.
After Narancia coughs up his tooth, Mista no longer observes that Narancia can't sit up straight.
The banana that ages along with Narancia now crumbles when he touches it.
Mista asking what's wrong with Narancia and Narancia explaining about the banana again now overlap each other.
A flower wilting and The Grateful Dead stepping on it as it walks down the train has been added.
As Narancia's fingers wither, him remarking that there is no blood flowing to them so he can't feel pain and Mista's internal reaction of shock have been cut.
In the manga, Bucciarati is shown grabbing Mista when he says they should let Giorno talk.
Before Giorno explains The Grateful Dead's ability, Bucciarati mentioning that he did not notice that Trish was taking the least damage out of the group has been removed.
When Giorno gives his explanation for how The Grateful Dead's aging effect discriminates between men and women, Mista now asks him if he's insinuating that Mista is a girl, rather than if the enemy was "checking [their] goods".
Mista no longer apologizes to Trish for this comment.
Bucciarati insisting Mista take the ice because it will take too long for the fridge to make enough for everyone has been removed.
This episode features a new version of the ending.
In the official English dub, this episode's title is changed to "Il Treno Espresso per Firenze".