This is a guide to all missables and points of no return in Fallout 4 (FO4). Check out all the missable items, quests, and companions in the game, as well as what points of no return to look out for, as well as how to avoid missables!

List of Missables

All Missables in Fallout 4
Ballistic Weave Legendary T-60 Power Armor Parts Astoundingly Awesome Tales #12 Lorenzo's Artifact Gun Mysterious Serum Piezonucleic Power Armor Paladin Danse 4 Missable Side Quests

Ballistic Weave from The Railroad

The Ballistic Weave is an armor mod obtainable by doing the Jackpot repeatable quests from Tinker Tom from the Railroad faction.

This armor mod is permanently missable if you advance the main game and complete The Molecular Level with the Brotherhood of Steel or the Minutemen without completing any radiant quests for the Railroad.

Ballistic Weave Adds Damage and Energy Resistance to Clothes

Clothing	Base Stats	Ballistic Wave MkV Stats
Mechanic Jumpsuit	DR: 0 ER: 0	DR: 110 ER: 110
Maxson's Battlecoat	DR: 50 ER: 0	DR: 160 ER: 110

The Ballistic Weave armor mod adds additional Damage Resistance and Energy Resistance to clothes, making them viable underarmor that you can further reinforce with armor pieces.

This armor mod is an almost requirement when doing Survival Mode as the extra damage and energy resistance will help you survive against Legendary enemies.

Legendary T-60 Power Armor Parts from The Brotherhood of Steel

T-60 Armor Piece	Location
Honor (Left Leg)	Obtained from Proctor Teagan after completing Blind Betrayal.
Vengeance	Obtained from Proctor Teagan after completing A New Dawn.
Exemplar's T-60c	Obtained after completing Duty or Dishonor by persuading Initiate Clark to turn himself in.
Visionary's T-60c Helm	Obtained from Lancer Captain Kells after completing A Loose End with any outcome.

Although it's possible to get T-60 Power Armor pieces from other locations, you can miss out on several named and Legendary T-60 armor pieces if you do not side or do side quests with the Brotherhood of Steel.

All Brotherhood of Steel Quests and Location

Astoundingly Awesome Tales #12 from the Institute

Astoundingly Awesome Tales #12, Have Dog, Will Travel!, is permanently missable if you do not collect it from the Institute and complete the main mission The Nuclear Option when siding with the Railroad, Brotherhood of Steel, or The Minutemen.

This magazine is obtainable from a balcony accessed through Clayton Holdren's quarters in the northern part of the Atrium.

All Magazine Locations Map

Lorenzo's Artifact Gun from The Secret of Cabot House

Lorenzo's Artifact Gun is permanently missable if you side with Lorenzo during the side quest The Secret of Cabot House.

You will need to side with Jack Cabot during the quest to receive this unique gamma gun mod.

Mysterious Serum from The Secret of Cabot House

Although it's possible to get 10 Mysterious Serum by doing The Secret of Cabot House and its associated side quests, these will eventually run out.

You can get 1 Mysterious Serum from Lorenzo Cabot if you have none in your inventory if you side with him during The Secret of Cabot House. Siding with Jack Cabot locks you from getting an infinite source of Mysterious Serum.

What to Do With Mysterious Serum

Piezonucleic Power Armor

The Piezonucleic Power Armor is a unique T-51 power armor chest piece that you can obtain from the side quest Cambridge Polymer Labs and is obtainable by completing the quest by properly combining U-238 with samples Sample 611 Gold and Sample 3111 Lithium hydride.

If you decide to initiate an override by accessing Dr. Bergman's terminal, you won't be able to obtain this unique power armor anymore.

Paladin Danse during End of the Line

Paladin Danse is the Brotherhood of Steel companion and it's possible to lose him if you decide to kill him or force him to commit suicide during Blind Betrayal at Listening Post Bravo.

To keep Paladin Danse, you'll need to Spare Him and then convince Elder Maxson to exile him during the conclusion of the quest.

Blind Betrayal Walkthrough

Exiting Listening Post Bravo Will Kill Paladin Danse

If you enter Listening Post Bravo and then leave without speaking to Paladin Danse (even if accidentally), he will kill himself and you'll permanently lose him as a companion.

4 Missable Side Quests

Side Quest	Availability Condition
The Marowski Heist	Only if Paul Pembroke dies and Henry Cooke survives in Diamond City Blues
The Memory Den	Before completing Unlikely Valentine only
Tradecraft / Plugging a Leak	If you do one, you can't do the other
Human Error	Before completing The Nuclear Option (any faction) only

There are 4 missable side quests in Fallout 4. Quests like The Marowski Heist require certain decisions in other side quests to unlock, while quests like The Memory Den and Human Error are missable if you progress too far into the main quest.

List of Missable Side Quests

List of Points of No Return

List of Points of No Return in Fallout 4
HP Debuff from Hole in the Wall Side Quest Faction Points of No Return Faction Followers

Permanent HP Debuff from Hole in the Wall Side Quest

It's possiblle to contract Mole Rat Disease if bitten by a mole rat during the Hole in the Wall Side Quest. This disease adds a -10 Max HP and is a permanent disease that can only be cured with the Vault 81 Cure. Companions bit by mole rats during the quest will cause you to get infected as well.

Choosing to use the cure on yourself will cause Austin Engil to die and will permanently scar your relationship with the Valut 81 residents.

However, it's possible to avoid getting bitten by the mole rats during the quest and still give Austin the cure though this requires some save scumming during the mission and you'll need to dismiss any companions during the quest.

Faction Points of No Return

Each major faction in the game has a mission that functions as a point of no return. Completing any of these will cause your character to permanently side with that faction, which means you'll need to eliminate the opposing factions.

Mass Fusion (The Institute)

This is the Institute faction point of no return. Completing this quest will cause you to ally with the Institute and will eventually lead to the quests End of the Line and Airship Down, which sees you take down the Railroad and The Brotherhood of Steel factions respectively.

Siding and completing the game with the Institute causes Deacon and Paladin Danse to become aggressive and will require you to kill them. Paladin Danse, however, will not become aggressive if you chose to spare him and gets banished at the end of Blind Betrayal.

Underground Undercover (The Railroad)

This is the Railroad faction point of no return. Completing this quest will cause you to ally with the Railroad and will eventually lead to the quests Rocket's Red Glare and The Nuclear Option (Railroad) which sees you take down The Brotherhood of Steel and the Institute respectively.

Siding and completing the game with the Brotherhood of Steel causes X6-88 and Paladin Danse to become aggressive and will require you to kill them.Paladin Danse, however, will not become aggressive if you chose to spare him and gets banished at the end of Blind Betrayal.

Underground Undercover Walkthrough

Tactical Thinking (Brotherhood of Steel)

This is the Brotherhood of Steel faction point of no return which sees you taking out the leaders of the Railroad. Completing this quest will cause you to ally with the Brotherhood of Steel and will eventually lead to the quest The Nuclear Option (Brotherhood of Steel) which sees you take down the Institute.

Siding and completing the game with the Brotherhood of Steel causes Deacon and X6-88 to become aggressive and will require you to kill them.
Tactical Thinking Walkthrough

The Nuclear Option (Minutemen)

If siding with the Minutemen to take out the Institute, it's possible to turn The Railroad aggressive if you do not issue an evacuation notice which is an optional mission during the quest.

Failure to do so will cause the Raildroad leaders to turn on you.

The Nuclear Option (Minutemen) Walkthrough

Faction Followers

Companion	Faction	Point of No Return
Deacon	The Railroad	Tactical Thinking or End of the Line
Paladin Danse	The Brotherhood of Steel	Airship Down or Rockets Red Glare
X6-88	The Institute	The Nuclear Option (Any Faction)

Siding with one faction will cause the opposing faction companion to become aggressive and you'll be forced to kill them. This includes companions that you've already maxed out your affintiy.

The exception is Paladin Danse who will stay friendly but impossible to interact with even if destroying the Brotherhood of Steel provided that they spare him and convince Elder Maxson to exile him during Blind Betrayal.

How to Avoid Missables

Explore the Commonwealth

Although the Sole Survivor's search for Shaun is a pressing matter, we recommend taking the time to explore the Commonwealth first since some side quests become unavailable after progressing too far into the Main Quest.

Exploring the Commonwealth also allows you to find Side Quests that you would normally not find if you focus on completing the main quest.

Full Interactive Map and Map Locations

Complete Faction Quests

Certain faction side and repeatable quests become unavailable after choosing a side near the end of the game. The Railroad faction, in particular, is the only source of Ballistic Weave which becomes unavailable if you side with The Institute or The Brotherhood of Steel.

We recommend holding off starting the faction quests Tactical Thinking, Underground Undercover, and Mass Fusion so that you can continue doing repeatable quests from all four factions.

All Factions List

Fallout 4 Related Guides

Beginner's Guide to Fallout 4: All Tips and Tricks

Fallout 4 Guides

General Tips and Tricks
How to Wait	Hacking Explained: How to Hack Terminals
Can You Respec?	Suggs Location
Best Starting Stats	Caps Farming
Supply Lines Explained	How to Level Up Fast
Jacob's Password Location	How to Get More Settlers
How to Fix Mysterious Signal Bug	Are Scavenging Stations Worth It?
How to Save Kent Connolly	What to Do With Mysterious Serum
Best Ending and All Endings Guide	How to Assign Workers
What is the Max Level? Level Cap Explained	How to Holster Weapon
List of Missables and Points of No Return	How to Tag for Search
How to Scrap Junk	How to Get Rid of Molerat Disease
How to Get Ballistic Weave	How to Get Grape Mentats