of women and children arriving, the risks are certainly on the rise. organised crime isn't the only menace. some refugees are forced to work for free, others to have sex in exchange for lodgings. the displaced and the vulnerable need our protection. katya adler, bbc news, on the polish—ukrainian border. away from ukraine, i want to tell you about this story. a group of investigators have put together a 3—d computer model of what a north korean detention centre looks like — giving us, for the first time, an idea of life inside one of the world's most notorious prison systems. the bbc�*s laura bicker, in seoul, has been given exclusive access to this 3—d model. laura, describe to us what the prison looks like.