Margaret Leighton has drawn heavily on journals and letters in recounting the exhilarating life of Mary Shelley: her childhood in a household frequented by poets and philosophers; the happy years with Shelley in Italy; the loss of her children and the ultimate tragedy of her husband's drowning. Long after his death, she kept her friendships with the figures whose lives had touched theirs - Byron, Leigh, Hunt, Trevelyan - as she single-mindedly pursued...