Riverside Manor is an imposing mansion overlooking the drained Summersville Lake, fading grandeur of Appalachia's old money. It was owned by Frederick, Shannon and Olivia Rivers before and after the Great War. It has a secret: A vast secret facility in the basement, intended by Frederick as an impossibly grand gesture to help her prepare for the role of the Mistress of Mystery on the small screen. Frederick's intention was to help Shannon prepare to portray the Mistress of Mystery in the upcoming Silver Shroud television series. That included acquiring a custom RobCo computer mainframe called Cryptos that was originally built for the Defense Intelligence Agency.
The facility became a refuge for the Rivers' during the Great War and the nucleus of the Order of Mysteries when Shannon and Frederick Rivers took in girls orphaned by the war. The Order of Mysteries was established to turn them into assassins, who would protect the people of Appalachia by eliminating threats such as the raiders. The underground facility became the secret headquarters to the Order where the members trained and received their missions. The facility was also equipped with a fabricator that can create or repair the Order's equipment. The facility was depopulated after Olivia Rivers' rampage, in reaction to the rest of the Order discovering her alliance with the raiders.
Riverside Manor is a large manor house built near the banks of the now-dry Summersville Lake. Down the road to the west are three Pulowski shelters which hide a secret elevator to the Riverside Manor basement. A large fountain sits in front of the house and stone lion statues flank the stairs to the main entrance. rhododendrons and soot flowers grow in the garden. The eastern wing of the house containing Olivia Rivers' former room is connected to the main house via a second-floor walkway, with the driveway passing underneath the walkway. There is a man-made pond with a small dock and a boat near the entrance to the east wing. The pond contains some snaptail reeds.
A large portrait of Shannon Rivers in her role as the Mistress of Mystery is the centerpiece of the manor's foyer. A set of stairs leads up to the second floor and directly east of the foyer is a sitting room with an upright piano that hides a secret entrance to the basement. The rest of the first floor contains various living areas, a laundry, and a kitchen and dining area containing a pool table and grand piano. There is a locked (Picklock 2) pantry in the kitchen which contains a refrigerator and some spices.
The second floor contains several bedrooms and a study. The master bedroom is directly opposite the top of the main staircase and features an ensuite and walk-in robe containing a locked (Picklock 3) safe. Down the corridor to the east is Olivia Rivers' room which is destroyed, save for her terminal which is locked and requires her login details to access. The corridor to the west leads to a study and some guest rooms. A set of stairs on this floor leads to the roof. The roof houses some junk, a toolbox, and a locked (Picklock 2) safe.
The Order of Mysteries facility is accessed through the parlor room. To open it, one needs the worn veil (found on dead women with a black dress and two green chevrons on it; there are twenty of them and the closest is in the wine cellar of the Hornwright Summer Villa). After reading the entry on the study terminal describing the facility, the folding screen on the left corner of the parlor will pull back and reveal a corridor leading downstairs. Past the laser beams and the fake wall is the Order facility.
The facility is centered around the Cryptos mainframe in its heart, which is used to obtain promotions and advance the quest. There are two main floors to the facility. The upper floor contains the infirmary on the north side, with a chemistry station, terminal, and a locked safe, the council chamber with a terminal on the southern side, and the Headmistress' office in the western corner. The headmistress' office requires Mistress-level access, which requires completing Seeker of Mysteries.
The lower floor contains the production wing on the south side, together with the fabricator terminal (used to manufacture Mistress gear) and three crafting stations (armor, weapons, tinker's). On the west side is the hall of trials (defunct), with a dressing room next to it. On the northern side is the depository (storage room). The long corridor to the northwest leads to a chamber with several Pulowski Preservation Shelters. The Pulowski Preservation shelters outside of the manor are secretly elevators into the basement. Once Into the Mystery is completed, simply activating the door while inside of the shelter will teleport the player character into the basement, but a worn veil or Veil of Secrets must be equipped to pass the laser grid. Using these shelters bypasses the Scorched inside and outside of the manor but mole rats spawn near the shelters.
- Holotapes and notes
- Order of Mysteries - Production log 194 - Holotape, in the lower southern room on the fabrication terminal.
- Order of Mysteries - Production log 209 - Holotape, in the same room, next to the weapons workbench on crates.
- Order of Mysteries - Production log 212 - Holotape, in the same room, next to the weapons workbench on a terminal.
- Order of Mysteries - Rank: Initiate, Order of Mysteries - Rank: Novice, Order of Mysteries - Rank: Seeker, Order of Mysteries - Rank: Mistress - Holotapes, dispensed by Cryptos.
- Order of Mysteries - The Blade of Bastet, Order of Mysteries - The Phantom Device, Order of Mysteries - The Voice of Set, Order of Mysteries - Cryptos holotape - Holotapes, also dispensed by Cryptos.
- Order of Mysteries - Council recording - Holotape, on the council chamber terminal.
- Order of Mysteries - Infirmary log - Holotape, underneath the manor in the infirmary accessible from the password-locked terminal.
- Two potential Vault-Tec bobbleheads:
- On the second floor, along the west wall of the corner bedroom.
- On the second floor, on the bureau outside the master bedroom.
- Four potential magazines:
- In the small laundry room close to the south exit onto the back porch, placed vertically between the washing machine and suitcase.
- In the northeast corner of the library, next to the dark red leather sofa, with an upturned coffee table in front of it, on the lowest bookcase shelf.
- On the second floor, in the corner bedroom, in the open green footlocker at the foot of the bed.
- In the upstairs guest bedroom, on a desk next to the guest bedroom terminal.
- Other loot
- Veil of Secrets, Garb of Mysteries, Blade of Bastet, Voice of Set, Phantom Device - Obtained from the fabricator.
- Fusion core - Sitting on a cart with a microscope in the basement near the weapons workbench.
Riverside Manor appears only in Fallout 76.