In this moving first episode, cameras follow Professor Gill performing surgery on all the volunteers to implant the device he has designed that enables delivery of GDNF to a deep part of the brain. The device comprises four catheters placed in the putamen (a part of the brain key in Parkinson's) that link to a port embedded in the side of the skull through which GDNF can be infused monthly.

The results are revealed of a six-year medical trial into a new treatment for Parkinson's. Can it give hope to ten million Parkinson's sufferers worldwide?