Walk in the Park

Walk in the Park is a quest in the Fallout 4 add-on Far Harbor.

Quick walkthrough

 * Talk to the welcome party
 * Follow Captain Avery
 * Defend the Hull
 * Talk to Avery
 * Talk to Longfellow
 * Go to Acadia with Longfellow
 * Talk to Longfellow

Detailed walkthrough
The boat pulls into Far Harbor, where the player character is greeted by two locals, Captain Avery and Allen Lee. Avery asks what they are doing here; the player character questions her about Kasumi. Avery states that Kasumi did come through the Harbor, just as a Harborman, the Mariner, sounds an alarm. Avery asks the player character to help defend the "Hull", the wall protecting Far Harbor from danger, in exchange for answers. Follow Avery to the top of the Hull, where the player character must help the people defend the area from two consecutive attacks by two brand new enemy types, gulpers and anglers.

When the battle is over, Avery will converse with the player character and Allen Lee about the Fog surrounding the town, how Allen believes it is the fault of a resident group from the Children of Atom, and the name of the synth colony that Kasumi came for, Acadia. Avery directs the Sole Survivor to Old Longfellow, a resident of Far Harbor that is the best chance for navigating the dense, radioactive Fog that surrounds the island, as well as asking them to help around the Harbor, starting the quest Living on the Edge. Find Longfellow in The Last Plank, the local bar.

There, the old guide will say that he's done escorting people into the Fog, though an easy Charisma check will convince him to help. He advises that the player character stock up on items such as Rad-X, ammunition, Stimpaks, etc. When ready, Longfellow will lead the Sole Survivor out of Far Harbor, giving them a piece of Mirelurk jerky for the road.

Leading through the dense Fog, Longfellow advises the player character on various aspects of the island, as they climb higher. At one point encountering a Child of Atom, the player character is warned that the synths are distrusted by the Children, though nothing comes of it as of yet. Longfellow leads the Survivor to Acadia, then offers them the use of his cabin and his services as a companion, ending the quest and starting Where You Belong.

Rewards

 * Longfellow's cabin as a settlement

Bugs

 * While on the way to Acadia, Old Longfellow could get knocked out quickly after leaving the entrance of Far Harbor. The reason is that the Old Longfellow is not always resistent against radiation. Open the console, select him and write setlevel 9100 (high as possible) to solve this problem.
 * Occasionally Old Longfellow will pop ahead a distance when the quest first begins. He will then run back down the mountain and restart the quest back in the town where it should originally start from. When you get back to the starting point he will then just stand there. Try running away from him then approaching him again and he should continue on the quest.
 * Due to his AI script if the player runs on ahead he can often stay in spots where he is scripted to say something. Because of this if you are to run ahead and talk to the worshiper of Atom while he is somewhere else, upon returning to the point with Old Longfellow, he will stay there and not do anything since the event can not happen. Reload an earlier save is the best solution