Half zombie epic, half cannibal gorefest, this unusual blend of two popular Italo-horror subgenres results in a high-octane thriller that delivers the gory goods. The story involves a group of former Vietnam POW's who contract a bizarre disease in captivity which compels them to eat human flesh. Needless to say, this makes assimilation into post-war American life rather difficult as the gestating disease takes hold on the returning veterans, whose cannibal instincts eventually fight their way to the surface. One such victim is commando Norman Hopper (John Saxon), who is bitten by one of the POW's during a rescue mission and carries the gestating contagion back home. When the soldier who bit him (John Morghen) is released from a veterans' psychiatric hospital after apparently being cured, he makes brief phone contact with Saxon before succumbing to an immediate relapse, leading to a gory rampage and subsequent shootout with police. When Saxon begins feeling the urge to munch -- first developing an appetite for the teenage cupcake next door -- he springs his fellow cannibals from the hospital, leading to another bloody confrontation with the police -- this time in the city sewers.