Fallout 4 Walkthrough Episode 14: Synth Retention & The Battle of Bunker Hill

Retrieving Gabriel and Fighting at Bunker Hill in Fallout 4 Episode 14

Episode 14 of our Fallout 4 walkthrough continues the Institute storyline with two major missions back to back. Father assigns us a Courser and sends us out to reclaim a rogue synth who has taken over a raider stronghold. After that success he immediately pushes us into a three-way battle at Bunker Hill. This episode covers Synth Retention and The Battle of Bunker Hill, including the coastal approach through Reeb Marina, Gibson Point Pier and Lynn Pier Parking, the fight on the Libertalia tanker, and the final confrontation on the roof of the Commonwealth Institute of Technology.

fallout 4 battle of bunker hill

Meeting Father and the Coastal Approach to Nahant

We begin inside the Institute by speaking with Father. He explains that a synth named Gabriel has gone rogue, wiped his memory, and risen to lead a raider gang at Libertalia. A Courser named X6-88 is already waiting for us on the surface. We teleport out and immediately come under fire from a group of Raiders right at the spawn point. After clearing them we cut through the coastal route, discovering Reeb Marina before continuing past Gibson Point Pier and the Lynn Pier Parking structure on our way to the meetup.

The path leads us to the Nahant Sheriff’s Department where X6-88 is waiting. We speak with the Courser, who has already begun clearing the outer defenses, and then move together toward the raider-controlled ships that form Libertalia.

  • Lore Fact: Libertalia is a floating raider fortress built from a network of wrecked boats and barges anchored off the coast of Nahant. The largest vessel, a half-sunken tanker, serves as the command center and is where Gabriel has established his headquarters.
fallout 4 x6-88

Boarding the Libertalia Tanker and Reclaiming Gabriel

With X6-88 at our side we fight through the raider-filled walkways and turrets that guard the approach to the main tanker. Once aboard we climb the makeshift towers and platforms until we reach the captain’s cabin. Inside, X6-88 provides Gabriel’s recall code. We speak with the rogue synth, use the code, and then eliminate his remaining raider bodyguards. X6-88 teleports Gabriel back to the Institute, completing the primary objective of Synth Retention.

We return to the Institute and report to Father. He is pleased with the result and grants us personal quarters. After a short rest he summons us again and immediately assigns the next operation.

fallout 4 gabriel synth

The Railroad Assault at Bunker Hill with X4-18

Father reveals that several synths have escaped and are being sheltered by the Railroad at Bunker Hill. He sends Courser X4-18 to assist us. We meet X4-18 near the settlement and receive the recall codes for the runaway synths. The moment the conversation ends, a full three-way battle erupts between Institute forces, the Railroad, and the Brotherhood of Steel.

We push through the chaos, enter Bunker Hill through a side route, and locate the utility basement hatch behind the market counters. Inside we find the four escaped synths. In this playthrough we choose to kill them all, including X4-18 himself, rather than reset them for the Institute.

fallout 4 the railroad assault

Crossing the Commonwealth to the CIT Ruins

After the fighting at Bunker Hill ends we teleport to the CIT Rotunda and then make our way on foot to the Commonwealth Institute of Technology. The walk is kept intact because the route through the ruins is easy to miss and the landmarks are not always obvious. Super Mutants and other threats still occupy parts of the old campus, so careful movement is required.

Speaking with Father on the Roof and Ending the Episode

We reach the roof of the Commonwealth Institute of Technology where Father is waiting. He discusses the outcome of the Bunker Hill operation and the broader implications for the Institute’s plans. Once the conversation concludes he teleports away, bringing both Synth Retention and The Battle of Bunker Hill to a close.

This episode of the Fallout 4 walkthrough covers the full retrieval of Gabriel from Libertalia, the three-faction battle at Bunker Hill, and the final meeting with Father on the CIT roof. The choices made here continue to shape the Sole Survivor’s standing with the major factions of the Commonwealth.