You’ll need to learn how to find Jerome’s flask in The Outer Worlds Peril on Gorgon DLC if you want to finish the Love is the Plan and the Plan is Death side mission. This quest tasks you with finding a man named Jerome and his wife (or widow…?) tells you to at least find his flask. So where is the flask location?
The Outer Worlds Peril on Gorgon DLC | Jerome’s flask location
Jerome’s flask is in the Gorgon Ruins part of Gorgon. You can tell when you first get there because the game will notify you and reward you with some experience. Jerome’s flask is in one of the apartments there. Go to the specific apartments in the above picture.
Go up two ramps to get to the third floor. Now go to the apartment to the right of the one with the “Evicted” sign. Go into that room.
You’ll see the Engraved Flask on the bed. Pick it up.
Here’s a map of where the flask is. Note that the big red arrow is pointing to the blue player arrow.
That’s technically all you need for the mission. However, you should go the extra step and find his journal, too. His journal is located in a nearby bar, as you can see by the red arrow.
Go into that bar and check behind the counter. You’ll see the journal-like computer you can examine. Do so to figure out Jerome’s mysterious fate.
Here is the map for the journal. This will confirm that he did indeed turn into a marauder. However, it doesn’t give you exact location or what he is doing now (both of which are still a mystery). You can go back to Leonara at that Sprat Shack to turn in the mission. She will reward you. But is he alive? That’s another question worth looking into…