The Grand Grimoire is an ancient artifact that is used for Witchcraft that was lost through the ages but was found by warlock Solomon Kent. After he was apprehended by the two Witnesses, the Grimoire along with Solomon's body were burned, only Frank Irving retreved the Grimoire before it was burned and took it to Jeremy Crane where he attempted the Awakening Ritual to awaken the powers of those with Witch heritage.
The Grand Grimoire was created by John Dee, whom was a student of the occult. He made the spell book to contain all of the dark spells that he obtained over the years so that he could lock them away. It has since then been lost to the world. According to Katrina, many magic circles have tried to find the book but had little luck.
In a 21st century Sleepy Hollow, the Grand Grimoire is one of the artifacts that will be auctioned in the Claridge Auction House. A 17th century warlock named Solomon Kent steals it and tries to activate its powers, only to fail as the Grand Grimoire is missing some pages. The missing pages of the Grand Grimoire were found in the auction house's warehouse. Solomon takes the missing pages and flees to the Pocantico Grove during the purging of the tides where he casts not a resurrection spell but a time traveling spell. Solomon would not complete the time traveling spell as he was killed in the ensuing battle against Ichabod, Abbie and Irving. Irving, upon dealing the finishing blow on Solomon, secretly takes the Grand Grimoire. When asked by Ichabod and Abbie, Irving declares that the Grand Grimoire burned away with Solomon's body.
The following morning, Irving meets with Henry Parrish to whom he surrenders the Grand Grimoire. Using the Grimoire, Henry tolled the fake Revolutionary Bell to preform the Awakening Ritual, but only three witch descendants were awakened very briefly. Then, Henry found his mother, Katrina, granting her the Grimoire and then performed the ritual with her. However, Ichabod and Abbie managed to foil their plan and killed Henry. Then, an utterly enraged Katrina used the Traveler's Spell from the Grand Grimoire to travel back in time to kill her husband, but Abbie managed to follow her back in the year 1781. With Grace Dixon's help and understanding of the Abiero Spell, Abbie erased the effect of Katrina's spell and managed to let both of them return to the present. Katrina, in sheer rage, tried to destroy Abbie with the Grand Grimoire's curse, but Ichabod managed to knock the Grimoire down from Katrina's hand and seized the chance to reluctantly kill her, saving Abbie from certain death. After this, the Grimoire was locked deep in the Archives for safety.
Around 2030, in an alternate future where Malcolm Dreyfuss had conquered America, an older version of Crane had sent Lara Thomas to undo everything that happened from the moment that Diana had become the Horseman of War. He sent her to retrieve the Grand Grimoire to cast the Traveler's Spell. After locating it in Malcolm's lair where it was sent after everything in the Archives had been seized by Malcolm, she was able to cast the Traveler's Spell and, despite Malcolm's efforts to stop her, go back in time. After correcting the past, the alternate future had ceased to exist.
|"This Is War"||"The Kindred"||"Root of All Evil"||"Go Where I Send Thee..."||"The Weeping Lady"|
|"And the Abyss Gazes Back"||"Deliverance"||"Heartless"||"Mama"||"Magnum Opus"|
|"The Akeda"||"Paradise Lost"||"Pittura Infamante"||"Kali Yuga"||"Spellcaster"|
|"What Lies Beneath"||"Awakening"||"Tempus Fugit"|
|"Columbia"||"In Plain Sight"||"Heads of State"||"The People vs. Ichabod Crane"||"Blood from a Stone"|
|"Homecoming"||"Loco Parentis"||"Sick Burn"||"Child's Play"||"Insatiable"|
|"The Way of the Gun"||"Tomorrow"||"Freedom"|