Detective Case Files

 is the miscellaneous chain quest for two sub cases in Fallout 4.

Synopsis
Two detectives, a missing person, and a former partner. Sometimes when business is booming its a bad thing. Whether its a former partner returning for help or another disappearance in a city racked by fear and paranoia...

Walkthrough

 * This is a shell quest that links together the two cold cases undertaken by Nick Valentine. Talking to Ellie starts the quest.
 * The first case to resolve is The Disappearing Act, tracking down a man who vanished in mysterious circumstances.
 * The next case, once all of the pieces of Mr Sterling are accounted for and the quest ends, is triggered by Marty Bullfinch's holotape received from Ellie, which starts The Gilded Grasshopper.
 * After that quest is complete, the player simply has to close the case by going back to Ellie. Note, it's entirely possible to complete this part instantly if the player has already resolved the Grasshopper quest.