The doctors show that your breath is just as unique as your fingerprints, and Dr Chris goes behind the scenes of medical drama Casualty to see how they make fake body parts look so realistic. Meanwhile, over in accident and emergency, one patient has a nasty infection on his cheek and another has something stuck in his ear!

Dr Chris and Dr Xand turn back the clock and look at what medicine was like in the First World War. They meet a Paralympian runner who swaps her awesome blade for a World War I leather leg, and they look at the little critters that infested the trenches. Then they set up a massive experiment to demonstrate how soldiers' bodies had to cope with the pressures exerted by huge explosions.