The Mechanical Engineering and Human History

The Mechanical Engineering and Human History is a book written by Alex Mikhaylov and published in 2015. The book has a copy placed in Grace Field House Plant 3's library and Ray can be seen reading it at some points in the manga and anime.

History
The Mechanical Engineering and Human History is a book written by Alex Mikhaylov and published in 2015. There was a copy of the book in Grace Field House Plant 3's library. The actual contents of the book are unknown.

Introduction Arc
The Mechanical Engineering and Human History was the most recently published book in Grace Field House Plant 3's library which led Emma, Ray, and Norman to believe the world was "normal" up until 2015 and something drastic happened to the world and humanity between 2015 and 2045.

Promised Forest Arc
Emma, Ray, and Norman's theory about the world is proven wrong when Emma and Ray ask Sonju what happened to the world 30 years ago, to which Sonju says the world has been the way it is for over 1,000 years due to an agreement made between humans and demons called "The Promise" and nothing much has happened since.

King of Paradise Arc
In a side story in Chapter 113, there is a flashback to James and Peter Ratri's childhood, in which Peter offers to help James carry a stack of books and in return James offers to read Peter a book of his choice and Peter chooses The Mechanical Engineering and Human History.

Human World Arc
In "The Promised Neverland offscene 027", the elderly man who takes in Emma in the Human World after she developed amnesia due to the promise with Him, is revealed to be named Alex Mikhaylov. Ray and Norman immediately recognize the name as belonging to the author of The Mechanical Engineering and Human History.