Template:Item/Series Mass Extinction Series is a collection of book items. These items can be found with the 'unique' tag at Science HQ in World's End. However, they can also be found without the 'unique' label in The Great Library in Black Scratch.
The first book was written by the current leader of the Machinists, Finch, the second was written by Sabina, the third was written by Atticus, and the fourth was written by Idad.
Sabina's opinion in Mass Extinction II is cited by Finch in The Lost Ancients I. ru:Серия книг "Массовое Вымирание"