A 3,000-year-old Egyptian sarcophagus lies in the National Museum in Rio de Janeiro, mummy detectives James and Ken return to investigate. Experts previously believed it had never been opened. Can the Museum confirm that is the case and that the person inside was not switched in antiquity when it was common to re-use coffins - or much later, before it was given to the Emperor of Brazil in the nineteenth century? But now it is speculated that it contains the body of one of the two Brazilian emperors from the 19th century. An endoscopy and an X-ray examination can provide information. And in our second investigation, the corpse of a Peruvian native who died around 1000 AD also raises questions.