In a small flat in a social housing complex near Caracas, Adriana Briceño holds up what looks like a piece of rubbish, but hidden on the old chocolate bar wrapper is a message. The words scrawled on it were written by her son and are addressed to Ángel Godoy, the boy's father and Briceño's husband, while Ángel Godoy was a prisoner in Venezuela's notorious El Helicoide jail. "Daddy, take this to sweeten things a little," reads the blue ink. "We love you." Originally built in the 1950s as a luxury shopping centre, El Helicoide was never completed and was later taken over by Venezuela's feared intelligence services. It became a symbol of government repression. A United Nations investigation documented it was where people who had been arbitrarily arrested or forcibly disappeared were taken and, in some cases, tortured. Recently released detainees like Godoy have described brutal conditions in interviews with the BBC.…