It has been a year since Curtis Craig was released from Greenwood sanitarium, where he has been through hell. All he wishes now is to live quiet, normal life: he has nice girlfriend, place to live and steady job at Wyntech Industries. However, lately it seems that Curtis is losing his sanity... or maybe someone tries to make him believe so: he sees and hears things which cannot be real, he suffers of psychotic episodes, nightmares and flashbacks, and if that was not enough - someone murders his co-workers in manner that only totally sick, psychotic mind could think of. Curtis suspects that Paul Warner, the corrupt and unscrupulous vice-president of Wyntech, is responsible to the current events and to his father's death which occurred many years ago. Unfortunately, both the obnoxious police officer assigned to the case and Curtis' psychiatrist believe he is lunatic, and would not listen to him. With no other alternative, Curtis starts investigating the murders, determined to prove both his innocence and sanity. The clues lead him to the mysterious "Threshold" project. Curtis' investigation of Threshold project confirms some of his suspicions: by using inhuman methods, Wyntech synthesizes and markets addictive drugs, disguised as pharmaceutical products - supervised by Warner, who would do anything to protect the Threshold project, including the murder of Curtis' father. Curtis believes that Warner is also responsible to his delusions and to the recent murders as well, but he is unaware that he has one more enemy, much more dangerous and unrestrained than Warner - an enemy who waited twenty years to execute his diabolic plan against Curtis. When Curtis finally confronts his secret nemesis, he must gather all his wits in order to protect his sanity and to put an end to the murders.