The Disappearing Act

The Disappearing Act is a quest in Fallout 4.

Quick walkthrough

 * Accept the quest from Nick Valentine's office
 * Search Earl Sterling's house for clues
 * (Optional) Obtain the key to Earl Sterling's house (Yefin Bobov was his friend and will give it)
 * Investigate the Mega surgery center
 * Obtain the key to the surgery cellar (obtainable from Doctor Sun if a Charisma check is passed)
 * Investigate the surgery cellar
 * Talk to Ellie Perkins

Detailed walkthrough
The quest starts after Unlikely Valentine has been finished.

Journal entries

 * At the ending: I discovered what happened to Earl - Doc Crocker killed him during a botched surgery. I need to let Ellie know what happened.
 * Finished: I told Ellie what I'd found - Doctor Crocker killed Earl and Now he's out of the picture as well. She said she'd break the news to the folks at the Dugout Inn.