Fallout 4: Hole in the Wall

Getting Curie and the Medicine Bobblehead

Hole in the Wall is a Quest that can only be started after having 1. first located and entered Vault 81 (which is recommended so you can buy Overseer's Guardian), 2. given blood to Dr. Forsythe in the Clinic there, and 3. waiting at least one day before returning. One of the Vault's children will have been bitten by a Molerat upon your return, and you'll be sent into a secret section of the Vault in order to search for a cure.

Precautions
First, it is highly recommended you do not bring a companion with you on this quest as you will risk getting a disease even if your own character doesn't get hit. It is very likely you'll get it regardless, and be forced into some self-sacrifice in order to complete the quest satisfactorily. Regardless of what you choose, you can still get Curie as a Companion (and maybe one day her special Perk) and the Medicine Bobblehead.

Starting the Quest
Head to the Clinic and have a meeting with the Doctors about Austin. From here, it's a simple matter of following Bobby to the Reactor area of the Vault. You'll learn a lot about Vault 81 and its main function (every Vault in Fallout 4 has a backstory with strange experiments).

Hidden Vaults and Molerats
Vault 81 has a secret vault, which Bobby will reveal. Inside, you will note a lot of dirt, which means molerats in this case. Their bite carries a pathogen that will leave you with a permanent virus, causing you to lose -10 HP. This is the same virus that little Austin has.

If you can avoid being bitten and didn't bring a companion it is unlikely you'll catch it and face no choice in the end. You can, of course, save before this happens and ensure no Molerat can reach you but it's hardly worth it and sometimes the game glitches out during quicksaves (molerat midair attacking you, despite not being there or you already have the disease).

Further down the hallways (it's very linear), you'll encounter some robotic resistance. Shouldn't be anything too hard. Continue forward and gather loot that seems useful, but be wary of the staircase up as you near the end due to a molerat ambush from both sides. Again, once you've passed the door marked Research the ambushes intensify.

It becomes quite hard to avoid contracting the Molerat Disease debuff and is hardly worth it given the marginal effect on your HP. At some point it'll be less than 5% of your pool.

Meet Curie
Either through the Expert-level terminal door or going around and facing another pack of Molerats, you'll finally meet Curie in her lab. Convince her to open the door.

Inside, the Medicine Bobblehead can be found on her desk. You can grab this as Curie explains there is only one dose of the cure for the Molerat Disease. Curie is now your companion and will follow you out.

Now, a Choice
When you return to the Clinic, you must decide to either save Austin by giving him the cure, or using it for yourself to eliminate the permanent -10 HP debuff on you. The drawbacks of the latter are that you won't quite be 'included' in this Vault and people will hate you (along with some Companions, if present) as Austin will die. Giving Austin the cure will give you a 10% discount at the store, a room in the Vault, and also allow you to loot almost everything in the Vault where it would've previously been stealing. You'll additionally receive a Syringer rifle (which can deliver drugs from the chemistry station). Given the enormous amounts of HP you can gain toward the upper levels, it's not worth worrying about the debuff, though PC players can cheat to remove it by using the below.

Use the discount to purchase Overseer's Guardian for about 200 caps less, and the expensive Overseer's armguards for about 900 caps less depending on your Charisma. Now you can either keep Curie as a companion or send her to one of your Settlements until you want her later. Curie's special Perk for maximum affinity is to give you a once-per-day emergency healing of 100 HP.

Cheat for the Cure
Open the console with ` (tilde) and type player.additem 00055F10 to get a second copy of the cure if you don't mind tainting your file with a little cheating.