'Attack on Titan' manga chapter 86 spoilers news: Dr. Yaeger's books to expose secret of titans, human history, and location of Coordinate

The Survey Corps has continued with their mission to reach the Yaeger residence in hopes that the house contains the answer to all the mysteries surrounding the malevolent titans and their part in the human history. Surprisingly, the previous chapter of "Attack on Titan" manga series has spilled the important tidbits regarding the background of human civilization and the creation of Titans.

The Survey Corp group, composed of Eren, Mikasa, Levi and Hanji has finally reached the house of Dr. Yaeger. The mysterious doctor, who happens to be Eren's father, may have something to explain the existence of the titans. Luckily for the group, they ended up finding three books belonging to Dr. Yaeger in the basement. When they opened the very first page of one of these books, they were shocked by the photo inserted into the page. The photo suggests that human civilizations are in fact existing outside the walls.

The upcoming chapter is expected to explain the rest of the contents of the book, as well as the other journals discovered by Eren's group in the basement. While it has yet to be confirmed what these books actually have to explain some of the world's biggest issues, the online publication has provided some theories about the books.

The three books may be representing the three major mysteries of the world, which are the history of the world, the true origin and nature of the titans, and lastly, the coordinate. The first book may have the true history of the world before the first Reiss King rose to power. The second book is expected to narrate how the monstrous titans are created, which will confirm or disprove the ongoing fan speculations regarding the origin of the titans. Lastly, the third book will tell the location of the Coordinate, the much-coveted power source in the series. The Coordinate will give a person the ability to control the titans at will, as well as to manipulate the memories of all clans residing within the wall.

The fans might think that the current development in the manga series will eventually lead to the much-awaited finale of "Attack on Titan," or "Shingeki No Kyojin" in Japanese. According to Geek, the final sequence of the hit manga series may be within reach at this point, as what the series' editor Shintaro Kawakubo has been hinting over the past several months. More big revelations are expected to come, including the secret about the titans, as the series approaches its end.