A secret surveillance operation uncovers a shocking case of human trafficking and modern slavery. Scores of young men and women are being kept as prisoners and forced into unpaid labour, working for nothing at a car wash in Bristol.Officers also investigate an online trader using the dark web to illegally sell potentially deadly diet pills. Pills like these have already been responsible for several fatalities in the UK, and the National Food Crime Unit is determined to stop anyone from selling these pills for human consumption.In another case, investigators catch-up with a cowboy builder with an incredible list of excuses and a track record for conning people out of thousands of pounds.