The Fireproof Secret Diary is an action item for all classes. It is an old, red book with a flame design framing the partially singed cover. The book is bound closed by a golden clasp lock.
With this item equipped in the action slot, it functions like the Spellbook Magazine. The player's hand emits colorful sparkles in the Loadout view and the player can pick up and cast Magic spells. When a player starts or joins a round on a Halloween map that has magic spells without a spellbook equipped, a notification is displayed, allowing the player to equip it or cancel the notice by the using the keys given in the notification. The notification repeats until the player equips a spellbook or leaves the Halloween map.
June 19, 2012 Patch
- [Undocumented] The Secret Diary was added to the game.
June 20, 2012 Patch
June 27, 2012 Patch (Pyromania Update)
- [Undocumented] The Secret Diary is one of the two Mysterious Treasures, along with the Capacitor, not incinerated into a small pile of ash. Despite the obvious fire damage to the bottom right corner of the cover, it was renamed Fireproof Secret Diary, and it is not valid as one of the crafting ingredients for the Pile of Ash.
March 12, 2013 Patch
- [Undocumented] Fixed background errors in the Fireproof Secret Diary backpack icon.
October 29, 2013 Patch (Scream Fortress 2013)
October 29, 2014 Patch (Scream Fortress 2014)
- [Undocumented] Added the Limited attribute to the Fireproof Secret Diary.
September 16, 2021 Patch
- Fixed the Fireproof Secret Diary not cloaking
- Equipping the Eliminating The Impossible set will change the Secret Diary description to "the deeds of hellish cruelty and none the wiser", with random characters removed, which is a part of a quote from the "The Adventure of the Copper Beeches" short story, part of The Adventures of Sherlock Holmes collection. When combined with the other items added in the June 19, 2012 Patch, the full quote reads "Think of the deeds of hellish cruelty, the hidden wickedness which may go on, year in, year out, in such places, and none the wiser."
Level 1 Secret Diary
Unlike other games we could mention, owning this won't trigger a sound file narrating secret diary entries. Why? Because we RESPECT THE PRIVACY of our characters. What are they hiding? Truly we live in MYSTERIOUS TIMES.