"If you have to kill one, kill the other also."

These were the words the renowned psychologist Dr. Susan Patterson had reluctantly uttered to Homicide Detectives Iris Williams and Annette Toni. Their topic of discussion, sixteen year-old Stacey and Jannifer McHill.

A few weeks after Iris and Toni's horrific confrontation with the twins — where Iris was force to shoot and kill Jannifer — Stacey McHill was sent to a facility for the criminally insane.

"If you have to kill one, kill the other also."

Meanwhile, a sadistic rapist/murderer is on the loose in upper Manhattan and he's targeting middle age woman. Iris and Toni must hunt down the maniac before all hell breaks out. But in the middle of the investigation, Stacey McHill escapes. Now, the warning Dr. Susan Patterson had given to Iris and Toni will come back to haunt the detectives like nothing ever before.