Key to the Past

Key to the Past is a main quest in Fallout 76.

Quick walkthrough
Acquire the following holodisk key fragments from various places across Appalachia:
 * Blackwater Bandits key fragment - Blackwater mine on the now feral glowing one Freddie Lang.
 * Trappers key fragment - On Walter Griswold's corpse in Huntersville.
 * Diehards key fragment - Obtained from the duplication terminal after finding the holotype on Margie McClintock's corpse in the Palace of the Winding Path.
 * Gourmands' key fragment - On Morris Stevens (progenitor wendigo) in the wendigo cave.
 * Cutthroats key fragment - Big Fred's BBQ Shack on the now scorched David Thorpe.

Return to Rose so that she can produce a "master key" from those key fragments. Then search for information on Rosalynn Jeffries at the Charleston Capitol Building and finally go to the basement of the Pleasant Valley Ski Resort to find a raider cache storeroom with various loot.

Detailed walkthrough

 * Rose tasks the player character with locating five holotape key fragments dispersed among the five raider gangs. To find out where to locate the keys, the player will have to first travel to the Blackwater mine and access the terminal in the foyer. This will provide a series of clues on where to find the keys.
 * The first belongs to the Blackwater Bandits. The key is found on Freddie Lang, a feral glowing one found deeper in the mine, in the bandits' encampment (the northern branch from the main tunnel). Kill her and collect the fragment.
 * The second belongs to the Trappers. Their encampment is found near the Devil's Backbone, and the Trappers note will point to the corpse of Walter Griswold in the center of Huntersville. Griswold's corpse can be identified by his camouflaged fatigues and is rigged to explode 30 seconds after being looted, in a similar fashion to a mini nuke detonating.
 * The third belongs to the Diehards. The player character has to travel to the Sunnytop Ski Lanes and find Margie McClintock's Holotape in the suite on the northern end of the building, by the terminal. Margie destroyed her holotape, but she instructed her lieutenant of what to do. His terminal, in the basement, by the rental counter, will point to the Palace of the Winding Path. Collect a copy of the tape from the duplication terminal on the ground floor, in the northwestern office, near the back porch. To access the terminal, one needs to acquire the palace admin password. It can be found in a dresser located in the cultists' quarters in the eastern wing by the courtyard.
 * The fourth belongs to the Gourmands. Their encampment is found at Bolton Greens. The Gourmands note on top of the main building leads to the wendigo cave in the Savage Divide. The key is found on Morris Stevens, now progenitor wendigo, found deep within the cave. Kill him and collect the fragment.
 * The fifth belongs to David Thorpe. David, now turned by the Scorched Plague, can be found at Big Fred's BBQ Shack. After fighting off the ghouls the reside in the area, the key can found on David Thorpe. Kill him, and collect the fragment.
 * Once all key fragments have been collected, return to Rose at the Top of the world and hand them to her so that a master key can be created. Rose has one final request: find Rosalynn Jeffries at the Charleston Capitol Building. Rosalynn's body is in the courthouse jail and can be located using the jail terminal to find a Doe, J. The holotape on the table explains Rosalynn was captured by the Responders, to be used as bait to lure David out of hiding.
 * Once all other tasks have been completed, one is then directed to the cache beneath the Pleasant Valley Ski Resort. It is located past the offices and the souvenir shop, down a staircase that leads to the luggage sorting room. The keycard lies under the door mat before the entrance. It opens the way and gets the player characters through the laser grid (the laser grid will not open otherwise). Inside the cache is a plethora of items and the broken uplink necessary to advance The Missing Link.

Bugs

 * When leaving the world mid quest, some or all of the key pieces may be gone from inventory upon logging back in, forcing the player to repeat the respective quest stages to acquire them again and being able to continue the quest. There is no known fix other than to finish the whole quest during one session to avoid triggering the bug.
 * The bug seems to be triggered most often as a result of the game being closed abruptly - by crashing, task killing, or using the ALT-F4 key shortcut. Avoiding those actions when possible and leaving the game world before quitting the game might help to prevent the bug from happening.
 * On the portion of the quest where the player character is asked to kill David, there will sometimes not be a tracking dot showing where Big Fred's BBQ Shack is.

Ключ от прошлого