This mansion was the family home of the Grandchester family, including Hannibal, Morticia, and their daughter, Lucy. The young girl allegedly became possessed and murdered her parents, was committed to a mental institution, then escaped and committed suicide by hanging in the attic shortly after her 18th birthday. An indeterminate time later, this house was converted to a tourist attraction, taking advantage of the high traffic from the nearby Nuka-World amusement park.
The house is locked, but entry can be obtained from the Protectron ticket taker working just outside the front entrance. The Sole Survivor can either buy a ticket, pick a ticket up off the ground by the Protectron's feet and present it to the Protectron, pass a Speech check to convince the Protectron that they are an employee, pickpocket the key off of the Protectron or destroy it and loot its remains.
This large building features several accessible floors. The tour of the building is linear, often locking the Sole Survivor within until the automated announcer finishes describing the current room and asks them to "please proceed to the next room." The tour moves through the main floor, right until the kitchen. In the kitchen is a Master locked door that leads to the basement. Inside the basement is a Novice locked door with a bloody scene containing six trader corpses and a glowing radroach.
From the main hall and from the kitchen are three stairs going to the second floor. The doors on the second floor accessible from the main room are all locked and need a key and are opened later as part of the tour. The door accessible through the kitchen is unlocked as it is part of the tour. The hallway upstairs is protected by an automated turret.
The second floor has several chambers. The first is rigged with gas and was used for seances. The gas can be turned off by using the terminal in the back left corner. The next hallway ends with dead end stairs and the bedroom of the child on the left. Adjacent to the child's bedroom lies the parents' bedroom, currently in use by Zachariah. In this room is a Master-locked door that leads to the attic, along with a locked exit to the building.
- Grandchester Mansion tickets - Sold by the ticket taker Protectron at the entrance of the mansion.
- Grandchester Mansion key - One in possession of the ticket taker and another held by Zachariah.
- 100 Paddle ball strings in ticket taker's inventory upon destruction.
- Nuka-Punch recipe - In the room with Zachariah.
- SCAV! issue #4 - On a wooden box in the attic, on the righthand side directly after entering the room.
- A mini nuke - In the attic, just behind the steamer trunk, inside a metallic cart.
- A Protectron model - In the basement, behind a Master locked door in the kitchen. After entering the room, it stands on the right on a tool board.
There are several encounters with a female child (presumably the ghost of Lucy Grandchester) that can't be targeted in V.A.T.S. and has no name attached to the crosshairs. The female child can be tagged with recon scopes and appears with the name "Girl":
- Before entering the house for the first time, staring through a window to the top right above the entrance, second window from the right. If one flies up to that room, they will see that the only door to that room is boarded up from the inside. The child never notices the Sole Survivor.
- When the Sole Survivor enters the house for the first time, on the second story running to the left.
- In the hallway just after the seance room, running left into her own bedroom.
- Entering the attic spawns the same child who runs left. The child will run through a door on the back left wall shortly after spawning. If the Sole Survivor opens the door, a loud, jarring sound will be heard and one will find a dead end.
- In the same attic, there is a boarded-up door, if the player character no-clips through they can see that the room is mostly untextured, but there is a visible window and a shelf inside.
- One may encounter a glitch where the girl runs past in the upstairs hall. It is possible to chase her through the kitchen to the "upside-down room," where she will stop. One can engage her with the "talk" option, but she will not reply, only stare.
- It is possible to stagger or knock the "Girl" character down with gunshots, but doing so deals no damage and causes no reaction.
- On the terminal in Zachariah's room, he mentions in his last journal entry that he thinks one of his Assaultrons is malfunctioning because he keeps inexplicably hearing a little girl's laughter.
Behind the scenes
- The system narration within the mansion is voiced by Kiff VandenHeuvel.
- The Grandchester Mystery Mansion itself alludes to the Winchester Mystery House, due to its similarity in name and history with supposed hauntings, seances and strange architecture meant to confuse spirits, such as doors and stairs to nowhere, windows overlooking other rooms, etc. The external appearance of the house and entry sign are almost identical to those of the Winchester mansion.
- The style of narration is similar to that of the Ghost Host heard in the Disney Haunted Mansion attraction.
- The story of Lucy Granchester lines up with the real-life Lizzie Borden, whose father and step-mother were murdered with an axe.
- Hacking to incite the Gunner Assaultron in the hallway beyond the seance room may cause it to chase the girl through the house. This will also cause a glitch preventing the player from proceeding any further through the mansion, needing to revert to a previous save file.[verified]
- When the girl runs past the Sole Survivor, through the séance room, and to the upside-down room, attacking the girl may similarly prevent the player from continuing further in the mansion, as an invisible wall blocks the player from moving forward.[verified]
- If you find the Grandchester Mystery House and do not enter the robot that grants access may no longer be there and you will not be able to get in.[verified]
- When loading the entrance auto-save, the tour may not start, thus the door opening it triggers don't open; at the same time there was an invisible wall upstairs preventing access to the seance room; both combined will restrict to the entrance room. Quitting then restarting the game did not fix it.