Billy's Halo

Science is just one way of looking at life. As a neuroscientist working at the forefront of medical research, it is Ruth McKernan's way.

For a while, it was her father Billy's too; science was a language they shared.

When Billy succumbed to a mystery illness and slipped from consciousness into coma, Ruth watched his life ebb away with a mixture of love and terror.

She struggled for control by using her scientific knowledge to analyse and understand his medical condition.

Billy had been a demanding father, the postman's son who became a self-made success - but it took his collapse for Ruth to realize just how intense her feelings were for him.

Now, she tells the story of her father's last year as a collection of cutting-edge scientific themes - memory, consciousness, microbes, stem cells - like pearls strung together on the thread of her father's life.

The result is an inspired blending of personal emotion, love and grief, with a crystal-clear scientific explanation of the way our brains and bodies work in sickness and in health.