In the heat of an American desert, Captain Jean Farrell arrives at a secret military installation, run by the enigmatic Doctor Harlan Jessup. Jessup is conducting 'Operation Sandman', an experiment involving a group of soldiers who have volunteered to be injected with 'the Juice', a drug which enables them to function without sleep. The team of soldiers, led by gruff and abusive 'Gunny' Riggins continually takes part in Virtual Reality scenarios whereby they face terrorists, kidnappers, guerrillas and a plethora of other situations that demand split-second timing, and undying obedience in the face of danger. They have continued for nearly three weeks without sleep, and their response times and reactions are better than ever. But there is a problem. As the test continues, the soldiers begin to see 'freaks', hallucinations that intrude on their consciousness and disturb their concentration. Jessup is on the point of getting government funding for the project and cannot afford hiccups, so Army Psychologist Farrell is called in to give the project a clean bill of health. But when she arrives, she discovers one of the soldiers is dead - he has apparently committed suicide using a hand grenade. But, she discovers, the shredded body contains no shrapnel, and there was no sound of an explosion. So, she wonders, how can a soldier be killed by a grenade that never existed?