What is the correct Islamic course of action towards a wife who refuses to return to the marital home, mistreats her husband's parents, discloses household secrets, and takes gold and official documents without permission?

The wife erred in several matters, including leaving without permission, refusing to return home, mistreating the husband's father, and divulging household secrets. The solution lies in applying the noble verse: "And if you fear dissension between the two, send an arbitrator from his people and an arbitrator from her people. If they both desire reconciliation, Allah will cause agreement between them. Indeed, Allah is ever Knowing, Acquainted." (Quran 4:35). If arbitration does not work, the matter can be taken to court. It is advisable to exercise self-restraint, perform Istikhara (prayer for guidance), and be patient, as well as to look for personal faults and rectify one's relationship with Allah.