Deeper magic

Bio
The Deeper Magic from Before the Dawn of Time was a different law written on the Stone Table before the beginning of time. It basically said that if anyone who had not commited a crime, and sacrificed themselves for another's crime, then death would work backwards.

History
Immediately following Aslan's murder, the White Witch Jadis's forces leave to prepare for battle. Aslan's dead body remains on the Stone Table. Susan Pevensie and Lucy Pevensie come out from their hiding spot and cry over his body. Shamed and humiliated, the girls are unable to face Aslan. They manage to remove the muzzle from Aslan, but they are unable to untie the cords around him. They then spend the rest of the night in a miserable daze, and cry until they cannot cry any longer, until eventually they return to Aslan's body, and see mice (ancestors to Reepicheep and Peepiceek) scampering over him. Susan raises a hand to scare them away, but Lucy notices that they are actually nibbling at the cords, trying to untie him.

The mice leave as dawn arrives, and Susan and Lucy walk around aimlessly as the sky brightens. The girls look at Cair Paravel when the first ray of gold breaks out over the horizon. At that moment, they hear a deafening crack. They whirl around, and see that the Stone Table has broken in half. Aslan has disappeared. Lucy asks if this is more magic, and a voice behind her answers that it is, indeed, more magic.

Susan and Lucy whirl around again and see Aslan, alive. They rush to him, and Susan asks if he is a ghost. Aslan alleviates their fears with one warm breath. To answer their question, Aslan explains that the Witch was right, that The Deep Magic had decreed that all traitors' lives are forfeited to the Witch. But if she had looked back before the dawn of time, she would have read a different incantation: -

"It means that though the Witch knew the Deep Magic, there is a magic deeper still which she did not know. Her knowledge goes back only to the dawn of time. But if she could have looked a little further back, into the stillness and darkness before Time dawned, she would have read there a different incantation. She would have known that when a willing victim who had commited no treachery was killed in a traitor's stead, the Table would crack and Death itself would start working backwards."

- Aslan describing the Deeper Magic.

Elated by this revelation, Aslan leads Susan and Lucy on a wild romp through Narnia.

Comments
Aslan's resurrection clearly parallels the resurrection of Christ. Moreover, the Stone Table on which he is sacrificed (inscribed with the Emperor-beyond-the-Sea's Deep Magic) evokes the stone tablets that Moses brought down from Mount Sinai—and Lewis acknowledged that he had Moses's tablets in mind when he described the Stone Table. The strange symbols and runes carved into this unimaginably ancient artifact seem to be relics of Old Narnians religion, the religion the Witch invokes when she calls upon the Deep Magic. Indeed, the Witch says that the Deep magic is carved into the Stone Table itself. When the Stone Table breaks, the event signifies the end of an era. Narnia undergoes a transition from an old, unforgiving faith to a new, vibrant, and compassionate one. The same thing can be said to have happened when Christ rose from the dead: God's old covenant with man was replaced with a new covenant. Aslan's suffering and death both renews and transforms the Deep Magic that governs the universe of Narnia.

Trivia

 * C. S. Lewis does not describe the fate of the mice that gnaw away at Aslan's cords, but he writes it in future books. Most of the animals in Narnia speak English. The mice, however, had never spoken. In all of the books following The Lion, the Witch, and the Wardrobe, mice have the gift of speech. Aslan explains that the mice can speak because of the kindness that they showed when they freed him. Aslan, like God, will reward all good deeds, even deeds by the poorest and lowliest creatures. The mice are exalted through this act of kindness, and transfigured by their generosity and good will.
 * Reepicheep and Peepiceek are descendants of those mice.