What is the ruling on a wife going out to study alone with male colleagues?

A wife's going out with men in a disbelieving country is not permissible and increases the danger and sin, as she is without a guardian, which makes her vulnerable to temptation and corruption. You are responsible before Allah for safeguarding her religion and honor, and you must reform yourself and your family. It is obligatory for you to repent to Allah and command your wife to return immediately from the lands of temptation, for preserving one's religion takes precedence over any other interest.