Now that you've finally made it to the Institute, your search for Shaun is almost at an end. Immediately leave the teleportation chamber and head east. As you walk across the room, a voice will ring out, imploring you to use the elevator down the steps ahead. When the voice falls silent, the final story quests - Institutionalised - will begin.
Note that you can carry out the Railroad's wishes and upload the encrypted message to an Institute terminal (as part of the Underground Undercover faction quest) at any time. However, you should hear what the owner of the voice has to say first.
Enter the elevator
At the foot of the staircase, step onto the elevator platform. The door will close automatically, taking you deep into the bowels of the complex. As you descend, the voice will reveal more about the Institute, confirming that he knows why you're there.
Once the elevator comes to a halt, make your way east along the corridor. At the end of the passage, step into the next elevator and press the button. When the elevator reaches its destination, enter the room ahead and approach the boy behind the glass. Draw in close, initiate a conversation and tell the boy that you've been looking for him.
Reveal that you're his dad and check if he's okay. Tell Shaun to open the door then, when he refuses, ask about 'Father'. Once the conversation is over, a man will step through the door to the right. Approach the man (who'll introduce himself as Father) and engage him in conversation. Inquire about his name then ask where Shaun is.
When Father reveals his true identity, tell him that he's crazy and demand to know why. Find out about the human synths, accept the man's story then work your way through the remaining dialogue options as you see fit. Once Father proposes that you join the Institute, agree so that you're able to explore the complex further.
Meet the division leaders
As the conversation draws to a close, Father suggests that meet the Institute's four division leaders - Clayton Holdren, Allie Filmore, Justin Ayo and Madison Li. Step through the door behind Father and climb the steps to the right. At the top, enter the bathroom directly ahead and swipe the bobby pins and RadAway from the behind the mirror.
Next, return to the top of the steps and move south. Take Shaun's terminal password from the office cabinet against the wall then loot the medkit on top. Next, locate the terminal to the right and use the password to access it. Read through Shaun's records, and note that you're unable to activate the 'synth shutdown' option.
When you're ready to continue, make your way through the doorway to the east and descend the staircase to the lowest level. Up ahead, you'll see Doctor Allie Fillmore (dressed predominantly in yellow) engaged in conversation with a synth.
Approach the doctor and, once she's finished talking to the synth, speak with her. When she asks, confirm that you're onboard with the Institute's plans. If you want to know more about the Facilities Division, you're free to question Allie now - otherwise bring the conversation to a close.
Once you're done talking, have a quick look around. You'll find a synth behind a counter to the left who'll happily sell you weapons, armour and other basic supplies. The doorway to the west, meanwhile, leads out toward the Institute's central hub - offering easy access to all four of the building's wings.
When you're ready to proceed, return to the foot of the staircase and head along the tunnel to the north - following the green line up the ramp and into the Bioscience lab on the right. Proceed along the corridor and enter the large circular room ahead. Doctor Holden - the scientist dressed predominantly in green - should be somewhere in the area, most likely near the terminals immediately to the left.
Approach Holden to introduce yourself then being working your way through the dialogue options. When he asks if you've decided to join them, tell him that you'd like to - then have him answer any of your questions. End the conversation when you've heard enough and prepare to locate the next director.
Before you leave the area, however, you should make a note of the master-locked terminal behind the partition to the north then head through the doorway to the north-east. On the other side, look for the Bioscience terminal on the desk then read through the files that it contains. Next, raid the lockers to the north-east then climb the stairs to the left, looting the adjacent room for medical supplies. When you're done, exit the Bioscience lab.
Back out in the hallway, take a right and head down the ramp. At the bottom, continue forward and follow the blue line toward the Advanced Systems lab. Take a right at the top of the slope and enter the laboratory.
Once inside, wait for the scientist to exit the room to the left and grab the ammo supplies. Next, read the research notes on the terminals to the east and north-east. When you're done, head through the door to the north-east and speak with Doctor Madison Li - the scientist dressed predominantly in blue.
Inquire about the department and the doctor will suggest that she installs a Courser Chip in your Pip-Boy, enabling you to fast travel to and from the Institute at will. Thank her then work your way through the remaining dialogue options to bring the conversation to a close.
Next, exit the Advanced Systems lab and head down the ramp to the right. Grab the medical supplies from the desk on the left then continue up the next slope, following the black line toward the Synth Retention lab. Take a right at the top then enter the lab.
Inside, follow the corridor forward and you'll immediately spot the final director behind the glass to the right, dressed predominantly in black. Once he moves into the next room, track him down and initiate conversation. Assure him that you won't cause any problems then, when you've learned more about his work, inquire about the synth escapes, explaining how you defeated the Courser. Work your way through the remaining dialogue options to bring the conversation - and the current objective - to a close.
Use the Network Scanner holotape
Before leaving the lab, explore the area and locate the terminal on the desk nearby. Read about the department's activities then select the 'Load Holotape' menu option. Finally, load the Network Scanner tape and initiate a scan to complete the current (and final) story quest. Note that selecting the 'Copy encrypted message' option will progress the Railroad's 'Underground Undercover' faction quest in your log. However, you might want to decide exactly where your loyalties lie first.
Once the Institutionalised story quest is complete, the Institute's fast travel option will become available on your map. Additionally, the Synth Retention quest will be added to your log - marking the first in a long line of Institute-based faction quests.
From this point on, you're largely left alone to complete the remaining available side quests and faction quests. Note that performing tasks for specific factions will cause your relationship with other factions to deteriorate. Eventually, you'll need to choose one faction to side with - whereupon you'll be close to discovering Fallout 4's true ending.
- Stuck somewhere else? Head back to the first page for the rest of our Fallout 4 guide.