Two years after the events of Iron Veins, the holds trade freely and old enmities have cooled to cautious trust. But trust is a thread — and some dwarves would rather cut it than share power.

When an earthquake opens a sealed chamber deep beneath Iron-Thorn Hold, Chief Archivist Lira Copper-Thread discovers a cache of encrypted Founding Era documents. She needs the one scribe who might crack the cipher: Varick Deepdelve, Senior Scribe of Emberhold — her reluctant former partner, whose methodical precision drives her absolutely mad.

As they decode the documents, they uncover something explosive: a secret clause in the Founding Pact that invalidates Iron-Thorn's ruling dynasty. The current steward inherited a lie she never knew existed — and Councilor Grimvar Deep-Fissure has spent three generations ensuring no one ever finds out.

What begins as a scholarly puzzle becomes a deadly game of cat and mouse through the deep tunnels beneath Iron-Thorn.