The Disappearing Act

The Disappearing Act is a quest that can be obtained within the Commonwealth, in Fallout 4..

Synopsis
A man by the name of Earl Sterling has gone missing within Diamond City, leading many to immediately assume that he was kidnapped by the Institute. Is the answer really that convenient, or there something more sinister going on within the walls of Diamond City itself?

Walkthrough

 * 1) To start this quest, the player has to pick up the Earl Sterling case notes at the Valentine Detective Agency. After picking up the Earl Sterling case file, Valentine's secretary, Ellie, will mention that the man had mysteriously disappeared one day, and has not been seen nor heard of since. The only clue is Sterling's home, where the player can find a surgery receipt laying on the floor by the sofa, stating that Earl was going in for surgery at the city's Mega Surgery Center.
 * 2) At the Surgery Center, the player will need to interrogate Doctor Sun, the medical specialist that shares the upper portion of the shop with the facial reconstruction specialist that resides in the shop's cellar. Two persuasion checks will reveal that Doctor Sun believes Sterling never went under the knife, as he disappeared before he could front the caps.
 * 3) While Doctor Sun is ignorant of his colleagues actions on the day of Earl's disappearance, there is a rather suspicious trail of blood next to the surgery cellar trap door (near Sun's equipment, not the main entrance to the treatment "room"). The cellar can be entered by either breaking in, convincing Sun to give up the key, or bribing him with 100 caps for the key, instead.
 * 4) Immediately upon entering the cellar, Sun's colleague is seen obsessing over the corpse of Earl Sterling, and must either be killed, as he has clearly gone psychotic with rage, or he must be persuaded to stand down and give himself up. In the latter case, the doctor will admit that he accidentally killed Sterling during surgery, and had hidden his body in the cellar before going mad and mutilating it even further, as seen with the missing limbs and head.
 * 5) Should the doctor be successfully convinced to give himself up, he will then quickly pull his gun on himself, before blowing his own brains out. Alternatively, he will take a fatal dose of Psycho.
 * 6) Doctor Sun will then come down after hearing the commotion, and will threaten to report the player to the Diamond City security. He can be talked down or blown away. Either way,the player needs to report back to Ellie and claim their reward.