Short answers, pulled from the story.
The Book of the Dead is a collection of ancient Egyptian magic spells written on papyrus and placed in coffins or burial chambers. It was used from around 1550 BC to around 50 BC to guide the deceased through the underworld, known as the Duat, and into the afterlife. The Egyptian name for the text translates as Spells of Coming Forth by Day.
The Egyptologist Karl Richard Lepsius coined the name in 1842, using the German term Todtenbuch, which translates to Book of the Dead in English. Lepsius also published the first major study of the text that year and introduced the numbering system for spells that is still used today.
The Weighing of the Heart, depicted in Spell 125, was the judgment ritual at the heart of the Book of the Dead. The dead person's heart was weighed on scales against a feather representing the goddess Maat. If the scales balanced, the deceased was declared vindicated and guided to Osiris. If the heart was too heavy, the creature Ammit devoured it, ending the person's existence.
The Papyrus of Ani is considered the finest extant example of the Book of the Dead from ancient Egypt. It was discovered in Luxor in 1888 by Egyptians trading in illegal antiquities and acquired that year by E. A. Wallis Budge of the British Museum, where it remains today.
As of the most recent scholarly count, 192 spells have been identified across surviving manuscripts. No single papyrus contains all of them. The spells were individually chosen by or for the deceased, covering purposes ranging from protecting the heart to preserving the soul's shadow to giving the dead power over supernatural guardians.
The Waziri Papyrus I is a 16-meter papyrus containing sections of the Book of the Dead, discovered in 2023 inside a coffin near the Step Pyramid of Djoser. Egypt's Ministry of Antiquities announced the find, and the scroll was named after Mostafa Waziri.