In the crown city of Helmspire, the Last True Vigilant, Enelda Drake, has returned. Enelda and her loyal guard Hawley are tasked with solving all manner of crime in the kingdom's capital. From missing jewels to lying nobles, she has solved it all. The realm's young king is delighted. His mother, perhaps the true power behind the throne, has her doubts.

But, after three years of simple cases, Enelda faces the impossible. An important noble has been strangled to death in a windowless vault. The only door was locked from the inside. Guards monitored the doors at all times. No weapons were left behind; nothing was stolen. And yet, the noble is dead.

As Enelda and Hawley barely begin to put together the pieces, there is another murder. Again, under shockingly impossible circumstances.

With two wealthy nobles slain, panic spreads quickly among the elite who have gathered in the city for a major festival. But they are not the only ones converging on Helmspire: allies, enemies, and the threat of ancient magic come knocking at Enelda's door.

With pressure mounting from the king, and the list of suspects growing daily, Enelda will need to prove herself, or reckon with the fact that maybe she's not the True Vigilant she claims to be.