Elara keeps the books for a failing mill. Her father tells the king she can spin straw into gold. She signs the contract before she finishes reading it - because it was that or execution, and the arithmetic favoured survival.
The contractor who appears in her locked room is not a monster. He's an exhausted subcontractor on depleted credit, billing fire-sprites at union rates. Night one costs her mother's ring. Night two costs her first memory of the mill. Night three costs a child she doesn't have yet.
She finds his true name. She speaks it. She breaks the contract.
She also triggers a cascade default across every magical economy in the region. The gold - all of it - was always straw.
The ledger balances. Someone always pays.
Spin is Rumpelstiltskin as debt spiral. Book 1/6 of the Thornevald Grimm Series. Dark, precise, and load-bearing.