Robin Penmarch has escaped the dark forces of the Uncertain World, and is back in the monastery where he studies magic. But there is a traitor in the Guild, and before long, Master Quadehar is falsely accused. Robin is determined to prove his teacher's innocence. Meanwhile, the mysterious Lord Sha has somehow infiltrated the monastery. What might the Lord's connection be to the stolen Book of Stars, which holds the secrets to bringing peace to the Worlds? Together with his friends, Robin goes in search of the truth. But he must prepare to face the greatest dangers of his life.