Harley Quinn joins forces with a singer, an assassin and a police detective to help a young girl who had a hit placed on her after she stole a rare diamond from a crime lord.

When his wife and daughter are senselessly murdered, a grieving man finds himself caught up in a war between a group of charismatic vigilantes and the crime that infests their city.

On Halloween night, a serial killer returns from the dead to take revenge on the vigilantes who put him to death one year earlier.

The Three Mesquiteers are forced to track down a train robbery ring after some of the gang hijack their truck for a getaway and the police conclude they are part of the gang, an identification which is just fine with the gang's nameless chief.