Azúcar Prieta by Edward C Distel

Havana, late 1825. Diego Armas Montoya arrives from Tenerife with forty-three pesos, a letter of introduction, and a ledger hand three merchants have called the best they've employed. He does not yet know it will be enough.

Sent to audit the debt-ridden Villanueva sugar estate in Matanzas, Diego finds a plantation held together by Isabel Villanueva — a woman running an inheritance the law will not fully recognize as hers — and a set of account books hiding a secret that could destroy the family that shelters it. As boundary disputes, colonial law, and a captain with his own reasons for watching the estate close in, Diego and Isabel must decide what honesty costs, and who is permitted to pay it.

Azúcar Prieta is a historical novel about ledgers and mercy, land and law, and the particular arithmetic of a colonial world where every number conceals a name.