Overdue Book

Overdue books are a recurring item throughout The Commonwealth of Fallout 4. When a book is returned to one of the special terminals, the player receives five book return tokens. The tokens can then be exchanged for a variety of prizes. The most notable of them is a copy of the Massachusetts Surgical Journal from a terminal in Boston Public Library.

Locations

 * Six of them can be found distributed throughout the Boston Public Library.
 * Three in the mechanical room, northwest corner of library, on the floor
 * One in the women's restroom in a stall (respawns).
 * One in the main reading room on a shelf
 * One in the secondary reading room on a desk
 * Eight in the Shaw High School.
 * Five can be found at Suffolk County charter school. One of them is behind an Expert locked door on the second floor (beware of glowing radroach), one on the counter outside the principal's office next to a broken terminal, one behind a large door with Novice lock in the kitchen area, one on the floor of the library on the second floor next to the dead body in a pink dress, and one in the basement, behind a door secured with an Expert terminal.
 * Four inside the Trinity Church: One can be found down the stairs behind the lectern at the east end of the main chapel hall, another on the bottom floor on the table, a third on a shelf on a bookcase on the west side of the bottom floor, and a fourth on a table on the bottom floor.
 * Four in D.B. Technical High School:
 * One on the ground floor between 2 damaged computers in the room with the overdue book return.
 * One on the second floor on a short bookshelf near a large portrait of water lilies in an area near a restroom above the cafeteria.
 * One in the chemistry lab on the second floor under a picture of a farm.
 * One on the second floor on a table lit by a nearby fire in a steel drum.
 * Three can be found in the Pulowski Preservation Shelter at the South end of Trinity Plaza.
 * Three can be found in Natick police department:
 * One in an open cell.
 * One in a trash can on the top floor of one of the offices.
 * One in the windows of the book store just south of the police station.
 * Two can be found on the ground floor of the Collegiate administration building.
 * Two can be found in Kendall Hospital. One in the lower levels. One on a shelf by a hole in the wall, to the southeast of the big fire.
 * Two can be found in the Subway station west of Hangman's Alley.
 * One can be found inside the ArcJet Systems building and can be picked up during the quest Call to Arms. One is sitting on the large table in the meeting room, which is located behind a closed door off the hallway where you encounter three machine gun turrets attached to the ceiling.
 * One can be found in the laundromat in Lexington, next to the diner.
 * One can be found beneath the counter at the Walden Pond gift shop.
 * One can be found on the lower level of USAF Satellite Station Olivia. It's resting on a cabinet in the middle of a small room. The room is across from a partially collapsed wall section off the larger two-story room with scaffolding.
 * One can be found in Faneuil Hall.
 * One can be found in a trader's shack west of ranger cabin, at the edge of the map. This one is marked as "owned" so you will have to steal it to acquire it, angering Preston, Codsworth and others.
 * One can be found in the Mass Fusion building, on the seemingly unreachable section of the fourth floor. You can drop down to the section from the fifth floor.
 * One can be obtained from Daisy of Daisy's Discounts in Goodneighbor. Ask her for work, and she will ask to clear out the super mutants holed up at the Boston Public Library. She'll give the book to the player if the quest is accepted and ask that they return it to a library terminal.
 * One can be found in Covenant, in a toilet behind the house with Penny Fitzgerald's store and Doctor Patricia's clinic.
 * One can be found in East Boston Preparatory School, on the counter in the first room on the right.
 * One can be found during The Big Dig quest. After you've sprung Mel out of jail and reconvened at The Dig, check the seats of the subway cars parked at the platform for it.
 * One can be found at Saugus Ironworks in the Southwest corner of the ground floor. It's behind a skeleton inside a smelting cauldron that's partially tipped on it's side.
 * One can be found in the Lockup at Quincy police station (basement) and there is a book return terminal on the 1st floor.
 * One can be found in Room 61 of Harbormaster hotel on top of a seated skeleton's lap.
 * One can be found at the top floor of Lexington Apartments
 * One can be found in the Boston Mayoral Shelter.
 * One can be found in the Pulowski Preservation Shelter in front of D.B. Technical High School.
 * One can be found in Bethany's shack to the northwest of ArcJet Systems.
 * One can be found in a Trader's shack north of the Mass Pike Interchange.
 * One can be found in the Parkview Apartments, on the first floor in a small bathroom under a skeleton inside of a bathtub.
 * Merchants may sometimes have one for sale.

Book return terminal locations

 * Boston Public Library.
 * Suffolk County charter school.
 * East Boston Preparatory School.
 * Natick police department.
 * Kendall Hospital.
 * Shaw High School.
 * Quincy police station.
 * Sandy Coves Convalescent Home.
 * D.B. Technical High School
 * A building next to Revere Beach station.

Book return terminal prize list
This is a complete list of all prizes available from the Book Return Terminals. Please note that the collectible baseball is not special in any way other than name, and Moe Cronin of Swatters has no interest in it.

It may be that there's a degree of randomness to the Book Return Terminals as people have reported items listed that others have not.