A rare sleep disorder, indeed Europe's only recorded case, turns a mild mannered 70-year-old man into a foul-mouthed violent monster at night.
Derek Rogers and his wife have 'nightmares' during the day, of the night to come. Once he falls asleep at night, Rogers wakes up soon after, a different person. He shouts, uses the foulest language, sleepwalks, hurts himself, punches walls and even tries to injure his wife.
Rogers has broken his nose thrice, cut his knuckles and head and bled profusely, and has even broken three ribs, all while asleep. The next morning he has not the faintest recollection of what happened.
After Rogers developed the sleep disorder, he started sleeping in separate beds from his wife to protect her.
The couple even placed a metal barrier between them. But it was not enough, as Rogers would climb over it to get to her.
Mrs. Rogers then moved to a different room to avoid her husband attacking her.
Mrs. Rogers says: 'He becomes like this other person. He is aggressive and his language is awful. He is just not the man I know. In his dreams, he gets very physical and starts punching the walls.'
Another side effect of the sleep disorder is insomnia - Rogers would stay awake for days, as he was scared of what he would do once he fell asleep.
Hope came when Rogers was referred to the sleep clinic at Papworth Hospital in Cambridge, after trying six different treatments for his dangerous disorder in other clinics.
Doctors finally discovered a drug that worked by breaking the circuit between the sleeping brains and muscles in the body, effectively paralyzing Rogers so that he could not harm himself or his wife.
For Rogers, the cost of a good night's sleep is now 25 thousand pounds a year. Yet anything's worth it, he believes.