The Grimoire of Alice is a spellbook owned by Alice Margatroid. In the PC-98 canon, she uses it against the heroine in the Extra Stage of Mystic Square, where she refers to its powers as "the ultimate magic"; "The Grimoire of Alice" is also the title of the BGM for this fight.
In the Windows canon, Alice is known to carry around a locked book; while never officially stated, this is widely assumed to be the grimoire, kept sealed due to her habit of never fighting at full strength. In Imperishable Night, she was seen carrying a book that appears to be the grimoire. Sunny Milk refers to Alice as possessing "a grimoire that shines wonderfully with all seven colours of light", though the truth of this statement is unclear.
Powers and Stats
Name: Grimoire of Alice, The grimoire "that shines wonderfully with all seven colours of light".
Origin: Touhou Project
Classification: Grimoire, probably Magical Amplificator.
Wielders: Alice Margatroid
Powers and Abilities: Magic
Attack Potency: Unknown
Weaknesses: Nothing notable.
Note: There are many hints that Windows Alice's grimoire is the same as PC-98 Alice's grimoire.