Someone attempts to take the life of writer Max Pomeroy, Tony Blake's friend. Upon investigation, Tony discovers an illegal gambling operation that Max is about to testify against before a grand jury. Tony gains the friendship of a disgruntled casino operative named Diane Thompson, and uses it to penetrate the casino's veil of secrecy. Using his card and dice handling skills, Tony is able to clean up on the house, but he soon finds his own life is in danger. His investigation culminates in a wild ride on the top of a hijacked ambulance.