Reunions

Reunions is a main story quest and achievement in Fallout 4.

Detailed walkthrough
Dogmeat has the scent of Kellogg and he leads out of Diamond City to a small pond to the south. There is another San Francisco Sunlights cigar which needs to be picked up and shown to Dogmeat to continue the search. He follows the trail along the railroad tracks where mole rats may be encountered. On the underpass, Dogmeat will stop in a doorway. In the nearby area there are signs of Kellogg's blood and showing the bloody rag to Dogmeat will continue the search.

The trail continues across a bridge to the remains of an assaultron that can be spoken to for more clues. Depending on which way Dogmeat leads through the forest, there is a possibility to run into a deathclaw sleeping in a small cave. On the outskirts of Fort Hagen there are bloodied bandages on a fence that are the next clue for Dogmeat to follow. Eventually the trail leads to the entrance to the fort where the doorway has been blocked.

Enter Fort Hagen either by a roof hatch or by an underground parking lot exit door. Inside the facility are numerous synths and automated turrets guarding the building. The Energy weapons bobblehead can be found in the kitchens of the command center. Deep in the facility, Kellogg begins talking to the Sole Survivor via the building's intercom advising them to turn back. Eventually the Sole Survivor comes to an office with a sealed door where Kellogg concedes that the Sole Survivor won't leave and opens the door so they can talk. During the conversation Kellogg will reveal that Shaun is being held by the The Institute and thus out of reach.

The conversation will end with both parties stating that the other must die and a fight breaks out. After Kellogg and his bodyguards have been killed a nearby terminal will reveal clues on where to continue the search for Shaun. The password for the terminal can be found on Kellogg's body, along with his Cybernetic brain augmenter which is needed for the next quest Dangerous Minds, and his unique gun, Kellogg's pistol. The terminal will unlock the security doors which leads to the exit. Note that a doorway which led into this final area will be closed and remain locked once the battle with Kellogg is started, preventing backtracking into the fort; the exit elevator becomes available at the opposite end of the same hall.

Upon exiting the fort, a short scene plays where the Sole Survivor witnesses The Brotherhood of Steel arrive in the Commonwealth in full force, having traveled from the Capital Wasteland with the Prydwen acting as their mobile base. Several vertibirds will escort the Prydwen as it travels across the Commonwealth. The Brotherhood will announce their arrival via a loudspeaker and state that they are coming with peaceful intentions.

Back at the Valentine Detective Agency or at Publick Occurrences (location), a conversation with Nick Valentine and Piper Wright will complete the quest.

Bugs
{{Notable content }}
 * {{platforms|PC}} After completing the quest, the Shadow of Steel may not trigger.{{verify|verified}}
 * {{platforms|PC}} After killing Kellogg, the Prydwen may not be seen in the sky and Military Frequency AF95 may not play. This can be fixed using the console command {{console|command=setstage 2bf21 1}} This will teleport you to the roof of the Cambridge Police Station and tell you to board the vertibird.{{Verify|verified}}
 * {{platforms|PC}} If Reunions is completed before Call to Arms, Shadow of Steel will not be triggered corectly, but The Prydwen will still appear, this might trigger a glitch with Brotherhood Vertibirds and patrols not spawn correctly, making them not appear at all or becoming really rare to find one of them.
 * {{platforms|PC|PS4}} Once Dogmeat has found Fort Hagen, he may become stuck at the front entrance until entering Fort Hagen. {{{Verify|verified}}
 * {{platforms|PC|Xbox One}} A game breaking bug maybe encountered while following Dogmeat, causing the game to crash to desktop after finding the bloody rags.{{verify|18:55, November 22, 2015 (UTC)|type=bug}}
 * {{platforms|PC}} If attacked while talking to the Assaultron, the quest may bug and never progress past this objective. {{verify|21:28, November 24, 2015 (UTC)|type=bug}}
 * {{Platforms|PC|PS4}} Upon entering the command center, Kellogg's synths may attack and prevent completion of "Confront Kellogg". This seems to be tied to wearing power armor when nearing the confrontation with Kellogg, but triggers earlier in the general area so that reloading an older save and exiting the power armor early in the basement level may be necessary to work around it.{{Verify|20:08, December 10, 2015 (UTC)|type=bug}}
 * {{platforms|PC}} During the discussion in Nick Valentine's office, the conversation may not finish and one will be unable to complete the quest. Loading from a previous save or restarting the game should fix it.{{Verify|20:08, December 10, 2015 (UTC)|type=bug}}
 * {{Platforms|PC}} During the end discussion between Nick, Piper and the Sole Survivor, the conversation may repeat after deciding who to travel to the Memory Den with. Going through it again, or leaving the building, will not have any negative effects.{{Verify|20:08, December 10, 2015 (UTC)|type=bug}}
 * {{Platforms|PC}} There is a bug where if you attempt to talk to Kellogg while wearing power armor he will become instantly hostile, a work around is to reload a previous save near the command center entrance and do not wear the armor while exploring. Taking off the armor near the encounter will not work.{{Verify|20:08, December 10, 2015 (UTC)|type=bug}}

Reuniones Воссоединение (квест Fallout 4)