- "Read immediately, your life depends on it! Greetings, traveler. I humbly invite you to my mansion for an evening of food and festivities with your fellow adventurers. Come to my home on the hill, just follow the path. Please look out for zombies. Sincerely, the Host."
- —The Invitation. src
Jesse, Petra, Lukas, and Ivor enter a dimension inhabited by zombies with two moons hovering in the sky instead of one. They find an invitation signed by an individual called "The Host", inviting them to their mansion to take refuge from the zombies and have a dinner party. They make a way through the overwhelming sea of zombies and race to the distant mansion. They run to the mansion, but the front door is blocked by zombies. They enter through a window on the second level by cutting down trees and making stairs with wood.
After breaking the window, the four arrive in the mansion's kitchen. The Gang is met by CaptainSparklez and TorqueDawg, two other guests who were invited to the mansion dinner. The four learn that the sea of zombies is not normal for this dimension, but the two moons are normal. After a short conversation, the lights go out suddenly, and TorqueDawg is killed by an arrow trap firing Poison Tipped arrows. The lights turn back on, and Jesse examines the crime scene, only to find that TorqueDawg's inventory is sucked into a tunnel.
LDShadowLady enters the room and recognizes Jesse and the others. She soon leads Jesse's gang to the main hall, and the gang is surprised to see that portraits of them are hanging on the wall along with portraits of the other guests in the mansion. They find that TorqueDawg's portrait has been crossed off with a big red "X".
CaptainSparklez takes the Gang to the dining room to meet the others in the mansion, including Cassie Rose; Winslow, Cassie Rose's cat; Stampy Cat; TheDiamondMinecart; and Stacy Plays. In the dining room, Jesse reveals to everyone that TorqueDawg has been murdered and determinantly reveals that he was taken out by poison tipped arrows. There are mixed reactions, and the house guests act very secretively. Jesse starts acting like a detective and questions the others about TorqueDawg and the Mansion, finding out that TorqueDawg was an infamous griefer and thief, that he claimed to have a "rare item", and that the groups are being very secretive and suspicious.
CaptainSparklez shows up and reveals that whoever who invited everyone to the mansion and killed TorqueDawg is probably after the Enchanted Flint and Steel possessed by one of the guests, and Jesse happens to have one. Jesse can choose to show Sparklez his/her flint and steel or hide it. However, as CaptainSparklez gathers everyone's attention and he sits to reveal this to the others, he is pushed by a piston into the floor and suffocated with sand. The lights go off again as he dies, and the mysterious "Host" reveals himself to be The White Pumpkin and threatens the group that he will resort even to murder to get the enchanted flint and steel. CaptainSparklez's inventory is sucked into a hole, similar to TorqueDawg's. Cassie Rose and Winslow try to escape but find that they are trapped in the mansion due to the sea of zombies outside.
- "Wait... so you're saying that the White Pumpkin is one of us?"
- "That's right, Mr. Stampy Cat, one of us... is a murderer."
- —Jesse and Stampy Cat.
The group then sees that CaptainSparklez's portrait, which is located next to TorqueDawg's portrait on the wall, has also been crossed out, just like TorqueDawg's. The group also sees that Ivor's portrait is next to CaptainSparklez's, indicating that Ivor might be the next to be murdered. Promising to protect Ivor, Jesse and Lukas head into the dining room to investigate.
Jesse finds that there was a button on the table which activated the trap and played a recording, and the "White Pumpkin" revealed during the show was only a costume on an armor stand. He/she reasons that the murderer must have pushed to button to activate the trap and that the murderer was sitting at the table when the murder happened. Therefore, one of the house guests at the dinner party is the White Pumpkin. Judging on the complicated traps and tipped arrows, the White Pumpkin must be an impressive Redstone engineer and brewer.
It is then revealed that there are actually multiple buttons on the table to activate the trap, and only TheDiamondMinecart, Stampy Cat, LDShadowLady, and Lukas were sitting at seats that had the buttons next to them, meaning that they could be the White Pumpkin. Jesse then interrogates TheDiamondMinecart, Stampy Cat and LDShadowLady in the interrogation order of the player's choice. He/she can question the three suspects about their Redstone and brewing abilities as well as their thoughts on who might have the flint and steel.
It is revealed during the interrogation that TheDiamondMinecart and LDShadowLady had been competing to find the Enchanted Flint and Steel for a long time, and TheDiamondMinecart found it first, much to LDShadowLady's disgust. Now, TheDiamondMinecart claims that someone has stolen the flint and steel from him. The suspects answer questions about Redstone and brewing differently depending on the order in which they are interrogated. Cassie Rose brings in Lukas and reminds Jesse that Lukas also had one of the buttons to activate the trap, but Jesse chooses not to question him.
Jesse has the choice to either accuse Stampy Cat, LDShadowLady, TheDiamondMinecart, or no one. If he/she accuses TheDiamondMinecart or chooses to accuse no-one, TheDiamondMinecart will retreat to the library. If he/she accuses Stampy or Lizzie, they will be locked up in the library. Lukas stays to keep an eye on them in case they "try anything" when Jesse is not looking.
Jesse, Petra, and Ivor head to the kitchen to further investigate the trap that killed TorqueDawg and sucked up his loot. Jesse sees a suspicious painting and notices that it has eye holes through which the White Pumpkin can spy on his victims. He/she then discovers a secret passageway behind the painting, which contains a lever that activates the trap that fires the Tipped Arrows. The three follow the secret passageway to the library, where TheDiamondMinecart, LDShadowLady, or Stampy Cat is held.
Jesse uses a painting with eye holes to spy on the person who is locked up in the library. Depending on who Jesse accused, either LDShadowLady or TheDiamondMinecart will visit TheDiamondMinecart, LDShadowLady, or StampyCat (whoever who is locked up in the library) and reveal that TheDiamondMinecart has accidentally pushed the button under the table and triggered the trap that killed CaptainSparklez. Suddenly, Jesse notices that the White Pumpkin is spying on them through a different painting. The murderer pulls a lever, and spiders are released and attack the group. The door to the library is blocked by iron bars, stranding the victims in the room full of spiders. The player can choose to either help fight off the spiders or punch the painting behind which the White Pumpkin is spying.
If the player chooses to help fight the spiders, Jesse, Ivor, Petra, TheDiamondMinecart/LDShadowLady/StampyCat (whoever who was locked up), and TheDiamondMinecart/LDShadowLady (who came to visit) successfully kill all the spiders, only the find that the spying White Pumpkin is gone. Jesse questions TheDiamondMinecart for killing CaptainSparklez, but all of a sudden, the lights go off again. The White Pumpkin comes into the room with a diamond axe and kills either LDShadowLady (if Jesse chose to accuse TheDiamondMinecart, LDShadowLady, or no one) or TheDiamondMinecart (if Jesse chose to accuse Stampy Cat). The murderer sweeps the victim's inventory into a hopper and escapes through a secret passageway. Likewise, if the player chooses to punch the painting, the White Pumpkin will come out with a diamond axe and confront Jesse. Jesse can slash a scar on the killer's White Pumpkin mask. However, LDShadowLady (if Jesse chose to accuse TheDiamondMinecart, LDShadowLady, or no one) or TheDiamondMinecart (if Jesse chose to accuse Stampy Cat) is killed by the spiders, and the White Pumpkin swipes their loot into a hopper and escapes through the secret passageway. Before everyone can enter the passageway, however, the entrance is shut, and Jesse has to chase the White Pumpkin, who attempts to kill him/her with tipped arrows and a lava trap.
The White Pumpkin breaks into the main hall, and Lukas joins Jesse as he/she chases the White Pumpkin. However, lights go off once again, and Lukas is left with the White Pumpkin mask in his hand. Lukas tells Jesse that the White Pumpkin caught him and stuffed the pumpkin on his head, but all other guests start to believe Lukas is the White Pumpkin because of how he had one of the buttons on the table and how murders only started happening when Jesse's gang arrived. Cassie Rose accuses Lukas and tries to lock him up, and Ivor agrees to watch over Lukas.
Jesse and Petra then discover another secret passageway behind a painting. After solving a puzzle, Jesse finds a huge empty shaft, and Petra becomes very annoyed of the other house guests. Jesse reminds her that they need to clear Lukas' name.
- "The White Pumpkin... is Cassie Rose. She's the murderer."
- —Jesse solving the mystery. (Determinant) src
Eventually, after crafting ladders to get down the tunnel, the two find zombie spawners, which proves that the White Pumpkin actually created the overwhelming number of zombies inhabiting the dimension. The passageway ultimately leads them to the White Pumpkin's secret lair, where they find a farm, where the murder grows white pumpkins. They then find Stampy Cat in the lair, who reveals that he has the lime green enchanted flint and steel which he stole from TheDiamondMinecart. Stampy Cat wants to give the enchanted flint and steel to the White Pumpkin in order to make everything stop.
In the lair, Jesse can grab some Ender Pearls that the White Pumpkin used to go down the empty shaft. He/she finds a chest filled with crossed-out portraits and dozens of calico cats. There is, however, no crossed-out portrait of Cassie Rose, and the calico cats look like Cassie's cat, Winslow, proving that the White Pumpkin is Cassie Rose.
- "None of you have ANY idea what I've been through! I've been stuck in this stupid world -- with its stupid two moons -- for YEARS. Trapped! With a portal RIGHT UNDER MY NOSE but no key to open it! That is, until I finally heard that this world's portal key had been found. I knew it was one of you... So I tried my best to earn your friendship. Figure out who had it."
- —Cassie's confession. (Determinant) src
Back on the top, Stampy Cat rounds everyone up, and Jesse accuses Cassie of being the White Pumpkin. He/she can prove it with the evidences that Cassie Rose was in the main hall when TorqueDawg's portrait was crossed out, that there is no crossed-out portrait for Cassie in the lair, and that they found calico cats resembling Winslow. If he/she provides enough evidence, Cassie will admit it. If he/she doesn't provide enough evidence, Stampy Cat will admit that he has the flint and steel, and Cassie will reveal her true natures. She reveals that she has been trapped in the two-mooned dimension for ages with an exit portal but no enchanted flint and steel to activate it and that she invited everyone to find out who has it by killing them and seeing if it is in their inventories. Eventually, Cassie Rose threatens to fight everyone and ultimately end up activating one of her traps and drowning in sand in her own trap, similar to CaptainSparklez.
At this time, the Sun comes out, the Zombies burn away, and Jesse's Gang part ways with TheDiamondMinecart/LDShadowLady, Stampy Cat, and Stacy Plays. As Jesse goes to light the "portal" back to the Portal Network, a trap is activated, and they fall into the Portal Chamber buried deep underground. It turns out that the portal they lit was not the real one, and the real portal is buried in the Portal Chamber all along. It is revealed Cassie is still alive and has faked her death. Cassie has suspended Jesse's gang above a pit of deadly Endermites as a final trap and threatens them to hand over Jesse's enchanted flint and steel. However, Jesse escapes the trap with an Ender Pearl that he/she found earlier in the lair. Jesse and Cassie Rose fight over Jesse's enchanted Flint and Steel; however, Jesse is able to overpower her with the help of the Gang, and Cassie falls into her own trap.
Cassie finally beckons for Jesse to give her Winslow, and Jesse can decide whether to do so or not. With the mystery solved, Jesse and the Gang head back to the Portal Network through the real portal.
- "Alright. What is going on, dudes? It's me, CaptainSparklez. Next time on Minecraft: Story Mode... After defeating the dreaded White Pumpkin, will Jesse and the others find their way back to the Portal Hallway? And will it lead them home? Or instead, are they destined for more perilous adventures? Well, I guess I'll never know because I got pounded into the ground by a ton of sand. I guess you saw that, right? I'm in the middle of an amazing speech, and BOOM! I've suddenly become part of the floor. I mean, dude, you saw that, right? How much worse can it get? First they choose NOT to invite me on their adventure, and the next thing I know, I'm part of the floor! Anyway, one thing's for certain: even withot me, this is going to be an amazing adventure!"
- —CaptainSparklez's epilogue to the episode. src