Alice Roberts uncovers the hospital's past and reveals how centuries of medical innovation continue to inform life-saving work in the modern day. She joins surgeon Henrietta Wilson as she prepares to use a million pound surgical robot to remove a cancerous lung tumour. Also, Alice recreates a grisly 17th-century operation on a 'patient' suffering from an enormous bladder stone.

Alice meets a 24-year-old cancer patient who has come in for urgent treatment, comparing the high-dose chemotherapy drugs he is given to those available in the apothecary shop set up in Barts in the 1600s. She also looks back at the Great Plague of 1665, asking medical historian Lesley Smith how modern-day medics would have dealt with the patients that arrived at the hospital.