A spell book that is completely empty but has a magical aura about it. 

This tome, once attuned, can store any casters' magic that has been counter spelled successfully by its wielder. The spell is entered into this book as if given the time and monetary requirements of copying a spell. 

For the next 24 hours, the spell can be cast from this tome without expending a spell slot. The spell is removed from the book after either casting it or the 24 hours has expired.