Far From Home

Far from Home is a quest and achievement/trophy in the Fallout 4 add-on Far Harbor.

Detailed walkthrough
After completing Getting a Clue, a new radio station will appear on the Pip-Boy, Valentine's Detective Agency, with a message from Ellie Perkins to come and see her; a new case has arrived. Upon reaching the agency Ellie informs of a new client, Kenji Nakano. The man's seemingly uneasy attitude points to the likelihood of a missing person case. One can also go straight to the Nakano residence and start the quest there without having to go the Valentine Detective Agency or completing Getting a Clue.

Travel to the Nakano Residence, north of Coastal cottage. Meet with Kenji and his wife, Rei, who inform the player character that their daughter, Kasumi, has gone missing, and want the Sole Survivor to help find her. Progressive questioning, besides some Charisma checks, leads the player character to the boathouse, where a holotape, locked in an Expert safe, with the key inside a picture frame on a desk, reveals that Kasumi made contact with a colony of synths near a northern location called Far Harbor, and their presence made her question her own humanity, causing her to escape to find out the truth.

Return to the Nakanos, and inform them of the discovery. Board the boat to Far Harbor, awarding the achievement on the spot.