This quest is given to the player either by Bigsley, when asked about water distribution problems, or directly by Lepelletier at the entrance to Rivet City. Found at an improvised command post at the shoreside structure linking to the bridge, Lepelletier will describe the problems they started having with the caravans. After a period of ease, where the loot from the war with the Enclave allowed them to effectively keep the caravan safe with minimal problems, they started losing shipments and officers at an alarming rate, to the point where just one in four makes it back.
She will then send the player out to link up with a caravan heading to Canterbury Commons from the Jefferson Memorial. The player will be told to catch up with them and speak with Davis and Lorin, providing additional protection against raiders. She expects the raiders will ambush the shipment, allowing the player to track down their base of operations. An Easy Speech check allows the player to obtain a plasma rifle with a few spare energy cells.
The caravan will make it as far as the Arlington Bridge before stopping. Once the player approaches the location, three bandits will ambush the caravan. The Rivet City guards will make a stand, likely aided by the scavenger camped out under the bridge, but saving them is difficult unless the player pre-places a follower near the ambush site. The caravan driver and the brahmin are always dead on arrival.
Jack is found at the Wharf surrounded by other gang members. The player can simply kill them all (using eg. the Anchorage War Memorial island as a vantage point) or try diplomacy. In order to get Jack to talk to them, they need to use the password (mirelurk stew). Jack can be persuaded to stop attacking the caravans by passing a difficult Speech check, arguing that the whole scheme is pointless due to water being free. They will kill Grandma Sparkle, then leave. Another option is to join the gang and challenge Jack for leadership.
Joining the gang
Upon joining the gang, the player receives a set of metal armor complete with the matching helmet and Jack will refuse to talk with them unless they wear it (or any other metal armor; wearing a suit already while talking will cause Jack to behave as if the player has already joined. There is no further interaction beyond this point, unless the player challenges Jack to a duel.
When challenged, Jack will offer the player three melee weapons (lead pipe, combat knife or nail board) to choose from for the upcoming duel. Given that the weapons have low hit points, it's advisable to bring a couple of spares before coming down to the Wharf, so that they can be repaired to full condition. Attacking Jack with any other weapon or fists will cause the rest of the gang to attack, as it violates the terms of the duel, as will the assistance of any follower or the Mysterious Stranger. Jack is a good melee fighter, making drugs or VATS a good choice to even the odds out.
After killing Jack and assuming the bandits did not aggro the player, they will suggest extorting Lepelletier.
If the player kills the bandits, eliminating the threat they pose, Lepelletier will thank them for their assistance and direct them to Scribe Bigsley for a major reward: Enclave power armor and matching helmet, a Gatling laser, a plasma pistol, and a stock of matching ammunition.
If the player joined the bandits, they will get the option to extort Lepelletier for either a lump payout of 500 caps (paid by Lepelletier) or a weekly 200 caps (collected from the bandits at the Wharf). Lepelletier will pay, but promise to kill the player if they ever talk to her again. True to her word, trying to talk to her again will cause her and other Rivet City guards posted outside to attack the player.
If the player joined the bandits, but reports that they stopped the raids, the bandits will attack the player when they return to the Wharf, accusing the player of backstabbing them.
The script governing the duel may misfire and cause the bandits to assume that the player used a non-sanctioned weapon and attack. Saving beforehand is advised.