Public Knowledge

Public Knowledge is a side quest in Fallout 4.

Detailed walkthrough
Asking Daisy in Goodneighbor about work reveals that super mutants have taken over the Boston Public Library and she will pay to have them cleared out. A series of speech checks can be passed to increase the reward from 200 up to 400 caps. She also requests the return of an overdue book to one of the machines at the library.

There are two entrances to the library: an advanced locked door on the west side of the building, or going through Copley Station. The library is filled with Protectrons and turrets waging war against the invading super mutants. Regardless of which entrance is used, the robots will be hostile to the player character as well as the super mutants, unless the player character speaks to the intercom next to the door prior to entering and passes a speech check to convince it that they are an employee of the library. If this is done at the western door, it will unlock the door as well, meaning Copley Station can be completely avoided with one speech check.

Once inside, an announcement will broadcast saying that super mutants are coming in from the station and the robots will flock to fight them. Once the wave is cleared, the Sole Survivor can then find one of the two book return machines to return the overdue book. After that, return to Daisy to complete the quest.

Companion affinity

 * It is possible to get two likes from Strong by haggling and refusing the quest, then dismissing him from Goodneighbor prior to accepting the quest in earnest.

Bugs

 * If the Sole Survivor returns Daisy's book into any book return terminal outside of the library, the quest will keep on telling the player character to return the book in to a terminal inside the library even after clearing it of super mutants and the quest says to return to Daisy. However, this will not affect the quest, as once the Sole Survivor returns to Daisy, the quest will be completed.
 * The quest will not start after talking to Daisy. She says all the dialogue and even tells the player character to return her book, but no book is given and the quest is not given.
 * The intercom at the back entrance does not say that the library is closed, but instead responds like a NPC (e.g. 'Huh?' or 'Yeah?'). This precludes the player character entering as an employee, which makes the robots hostile. One can avoid the hostile reaction by entering the console command: . One must still pick the lock to enter the library, but the robots will not be hostile.