These are the harrowing conditions under which a teenager was locked up for two years by his father who believed neighbours were trying to poison them.
The terrified 19-year-old was only freed after he managed to send a frantic message to the police, bypassing filters his father had set on the computer to stop him.
Neighbours said he weighed as little as 6 stone and two ounces when he was carried away by rescuers in a blanket - a healthy weight for a 12-year-old.
Officers said he was suffering from malnutrition, dehydration and disorientation after enduring a catalogue of abuse, both physical and psychological.
The boy was locked up in the Rivas Vaciamadrid district of Madrid and a video released by the Spanish police shows the filthy and cramped conditions he was kept in.
There are bars on the window and wood and scrap metal all over the first floor of the property so he could stray no further from the landing.
The boy was taken to a hospital where he underwent a thorough health examination. He is now living with his mother and sisters.
Both the father and son are from India but are reported to have also have British nationality.
The terrified teenager managed to send an email to the police on firstname.lastname@example.org revealing his plight and asking for help.
He was also able to send contact details for his sister who confirmed his claims and a police raid was made on the family's home after obtaining a search warrant.
The email is said to have read: 'Rescue. Assistance. Help me. I am desperate. My father abuses me. I am held prisoner. Please, do not get in touch with me because he would kill me.'
A police spokesman said: 'When officers entered the house, they found the boy with severe physical symptoms and extremely thin.
'He was disoriented and suffered physical injuries from the beatings he had received from his father.'
Police said the teenager's computer had been blocked from certain sites but he spent so much time in his room that he managed to devise a way to get round the filters.
The father is reported to have mental problems and believe neighbours were trying to poison them through the water system and that he was being targeted by the Russian mafia.