In this series celebrating the life-changing work of the health service, 70 years after its creation, Dr Aarti Jagannath meets the neurosurgeons at the John Radcliffe Hospital in Oxford whose revolutionary surgery can offer hope to some patients battling the life-limiting tremors of Parkinson's, and help others walk again after years of constant pain. She also explores the 300-year-old ties between the University of Oxford and the hospital and reveals how pioneering research is now making mind control a reality.