The fourth Toaru Majutsu no Index light novel volume was first published on December 10, 2004. The story focuses on Touma's vacation due to the aftermath of the previous volume and gets to spend some time with his parents. However, he is later caught in a magic spell that can threaten the world. Not only that, he meets another Necessarius magician—Kanzaki Kaori, a magician from—Annihilatus Sasha Kreutzev, and discovers an old friend has a certain secret —Tsuchimikado Motoharu. Little did he know, that one member of his family also carries a secret of their own, forcing Touma to confront his long forgotten past.
A certain magic spell is to blame.
Kamijou Touma finds himself in the middle of the unfolding of the mysterious spell "Angel Fall"!
- Prologue: Parallel World of the Real World
- Chapter 1: The Magic World's Hex Suspect
- Chapter 2: Detective of the Battling World
- Chapter 3: Angel Force of the Harmful World
- Chapter 4: The Last Wizard of the Single World
- Epilogue: My Betrayer of the Everyday World
|어떤 마술의 금서목록 4|
|Release Date||June 11, 2007|
|Number of Pages||310 pages|
| 학원도시에서 외출 허가를 얻어 가족과 함께 바다로 바캉스를 온 카미조 토우마.|
거기서 그가 본 것은 어머니가 인덱스이고, 인덱스가 파란머리 피어스고,
|Release Date||  July 1, 2008|
June 5, 2012
|ISBN-13|| ISBN 978-986-174-734-7 |
但是這時怪事發生了，母親成了茵蒂克絲，茵蒂克絲成了藍髮耳環， 神裂火織成了史提爾，史提爾成了海邊大叔，御坂妹妹成了海邊大叔的兒子， 御坂美琴成了當麻的妹妹!?為什麼會這樣？ 原因似乎是「某種魔法」！神秘魔法「天使墜落」正以上条當麻為中心向外展開──!?
|A Certain Magical Index Volume 4|
|Release Date||August 18, 2015|
|Number of Pages||224 pages|
|Toma Kamijou has gotten permission to leave Academy City and goes on a beach vacation with his family. But somehow now his mother is Index, Index is Pierce Aogami, Kaori Kanzaki is Stiyl Magnus, Stiyl is a crusty old sea dog, Misaka's little sister is the sea dog's son, and Misaka is Toma's little sister--and a certain magical spell is to blame for everything! Toma's caught in the midst of the mysterious Angel's Fall spell in the latest volume of the smash-hit light novel series!|
- ↑ 1.0 1.1 とある魔術の禁書目録（4）（著者：鎌池和馬） from ASCII Mediaworks. Retrieved on 2014/1/10.
- ↑ 어떤 마술의 금서목록 4 from NT Novel (Korean). Retrieved on 24/07/19.
- ↑ 3.0 3.1 3.2 3.3 魔法禁書目錄 (4) from Kadokawa Taiwan (Chinese). Retrieved on 10/19/2015.
- ↑ 4.0 4.1 A Certain Magical Index, Vol. . Hachette Group. Retrieved on 05/20/2014.