One in 50 adults in Britain has their sleep invaded by dreadful attacks of night terrors. They wake up screaming, with overwhelming feelings of horror. This is the personal story of three people who have each suffered for more than 20 years. Rosemary and Clyde nearly killed themselves by sleepwalking through windows. Moya was misdiagnosed as epileptic. What lies behind their mysterious attacks? What kind of medicine will help?