Heat and Dust — Ruth Prawer Jhabvala

In 1923 the beautiful, spoiled, and bored Olivia, married to Douglas and his career in the Indian Civil Service, outrages the English and Indian communities by eloping with an Indian prince. Fifty years later, Douglas's granddaughter, armed with Olivia's letters, goes back to the heat and dust and squalor of the bazaars to find out for herself how Olivia could have been so affected by India that she turned her back on her own country.