It is not difficult to see why the publisher expects Relativity to find a wide readership; centred on Ethan its eccentric, physics-obsessed young protagonist, this is a touching portrayal of a fractured family.

Claire has always known her son is special, with his talent for numbers and precocious knowledge of astronomical facts. At school, his peers call him ‘Stephen Hawking’, but to Ethan this is ‘the greatest compliment’. Claire gave up her career as a ballet dancer in order to raise her son. Despite Claire’s loneliness and the unspoken mystery of Ethan’s absent father, the two have a loving relationship. When Ethan’s estranged father, Mark, contacts Claire in an effort to fulfil his own father’s dying wish to see his grandson, several coincidences coalesce to draw Mark back into their lives.