The Secret of Cabot House

The Secret of Cabot House is a quest in Fallout 4.

Detailed walkthrough
When returning to the Cabot House after saving Jack's sister, the player character will get this mission assigned by Jack to help prevent raiders from freeing Lorenzo. Although one can actually fail in preventing the raiders from freeing Lorenzo, the Sole Survivor still has to kill them all once Lorenzo is released.

OR
 * Upon flipping the switches and killing Lorenzo, Jack tells you Lorenzo would have killed his family as well as the player. He says his family influence was the only thing keeping his father in the asylum as opposed to Death Row due to his crimes during his life. Jack says that now that the world is "built for monsters", nothing would have stopped his father from presumably returning to criminal activity. You can choose to thank him or berate him for being sad only because he "lost [his] mortality juice"; though Jack seems to genuinely believe he could have removed the artifact and cured his father with a little more research. He awards you with about 500 caps and tells you to return to his home in about a week. He gives you a slightly different amount of caps depending on what you say following killing his father.
 * When an in-game week has passed, you will receive a notification that tells you to visit Jack back at the asylum. He tells you he figured out how to access the telekinesis effect of the artifact. He gives you Lorenzo's Artifact Gun.


 * Choosing to save Lorenzo by pushing the switch by his door will prompt Lorenzo to leave his cell; him saying he wants to have a "long overdue" conversation with his son. He tells you "we'll have to kill him, you know. And the rest of them." He tells you his son trapped him in there in 1898; nearly 400 years before the in-game date.
 * Arriving to Cabot house, Jack will ask why you freed him. The next conversation options will allow you to either help Jack further by saying you can help him, or help Lorenzo by saying he is wrong and then killing the Cabots. Whatever you choose to say, Lorenzo will appear on the balcony overlooking the family room. Wilhelmina tries to sell Jack out by saying she would never allow him to do what he did, but Lorenzo berates the family for feeding on his blood. Lorenzo then turns hostile to the Cabots (and the Sole Survivor if that option is chosen).
 * After killing him, Jack will reward you 502 caps, saying he no longer needs your services. Every quote from him following quests' end either mourns his lost family or berates you for not listening to him.
 * (If however successful in keeping every family member alive, asking for more rewards allows you to come back in a week to receive Lorenzo's Artifact Gun.)
 * Otherwise, after killing the Cabot family, Lorenzo will offer a "lifetime supply" of Mysterious serum, i.e., one at a time, which cannot be sold or traded away.

OR


 * The following describes the details for Plan C in which you free Lorenzo and then kill him before he leaves the area that is outside his cell.
 * You can activate up to 3 switches and still open the door of Lorenzo's cell to let him out.
 * Once he is out you can speak with him to find out what he intends to do.
 * Then you can engage and kill him pretty easily. Just stay out of his melee and "force push" range and shoot him until he dies. His "force push" doesn't do a lot of damage if your damage resistance is over 115 or so but it does stagger you and it prevents you from aiming properly for a moment. Lorenzo's gun is a low damage pipe pistol that doesn't do very much damage. Lorenzo does have a lot of health so it will take some time to kill him if you don't feel like wasting explosives or high-damage ammo on him.
 * Return back to Cabot house and Jack will be upset that you set Lorenzo free, but then you can tell him that you killed Lorenzo and that you are sorry that you did so. He will give you the 500 (or so) caps.
 * After a week you can return and Jack will give you Lorenzo's Artifact Gun.

Bugs

 * Jack Cabot sometimes spawns on the other side of the unpickable door leading to Lorenzo in the basement, preventing the quest from proceeding.
 * It can be fixed by forcing the door to open (with console command "unlock") and when Jack gets back to the player then closing the door (with console command "lock").
 * Completing the quest in Jack's favor may incorrectly display the quest completion text in the Pip-Boy as if you helped Lorenzo. This does not seem to affect earning the artifact gun reward.
 * Items within the Cabot house respawn at least twice during the mission.
 * Once you enter the asylum, there are 2 different doors right in front of the player with chains in them. If you have Cait with you, and get too close to the wall on the right side of the middle door with chains, near the broken window facing the courtyard, Cait will open the door and head into the yard. Jack, who might have gone ahead by this time, will come back into the room and will be hostile and start shooting. Attacking him until he falls down, will stop the hostility as he resets once up.
 * The door to the right of that, has broken panes above the door. Jumping (easier to do in power armor) while spamming the chain unlock button will eventually allow the door to open. Jack will come back once you enter and immediately run up to the ghoul and commence dialog
 * After siding with Jack and killing Lorenzo, the last step is to "Talk to Jack Cabot about the artifact." Attempting to talk to Jack, however, will not start the necessary speech check to end the quest. Jack will only offer small talk such as "Oh, it's you" therefore leaving the quest indefinitely unfinished.
 * After siding with Lorenzo and killing the family if you get caught looting the house Lorenzo attacks you. If you kill him the quest will not finish and there will be a talk to Lorenzo marker over a blank spot in the house where you killed him.
 * If the quest ended by killing Lorenzo after releasing him, but with Jack, Wilhelmina and Emogene still alive, player can kill either Emogene or Wilhelmina or both inside the house. This will make Jack turns hostile, but player can choose to leave the house and come back again a few days later to talk to Jack. Jack will have mixed dialogues of where he relieves that the family members are all alive and also blames the player for his mistake of releasing Lorenzo that results the death of Emogene or Wilhelmina, but player can still receive Lorenzo's Artifact Gun after a week has passed.
 * Jack will somehow turn hostile if he sees the player picks lock a "Master" safe in the basement of his house, despite the safe has no red text and all items in the house have no "Steal" option.

Тайна дома Кэботов