Graz is an inventor, utterly obsessed with magic and its hidden history. While following clues toward the source, he meets a human woman investigating the very same ancient ruin—unleashing a rivalry between them to get to the next clue first.

As a member of the King's History Corps, it's Vienne's job to reveal what she learns to her boss, but now that she's seen the power of magic for herself, she wonders whether it's safe to spill its secrets before she can uncover the truth for herself.

Soon, Graz and Vienne both begin to experience a magical sickness. But when a taboo spark erupts between them, magic will either save them—or doom them.