Behind the Mask follows federal agent Jack Hart (played by Jack Holt), who goes undercover as a convict named Quinn to infiltrate a drug-smuggling ring. The operation is led by a mysterious figure known only as Mr. X. To earn their trust, Jack stages a prison escape and joins the gang’s inner circle.br br The gang uses a fake hospital as a front, where victims are murdered during bogus surgeries. The drugs are hidden inside coffins and buried in a cemetery, using funerals as a cover for their trafficking operation.