Philomena is requisitioned from a Dorset field in the summer of 1914, and serves with the yeomanry in Egypt and Palestine until the end of the First World War. But she doesn't come back to England: thousands of British Army horses are sold off locally. Faint news of her reaches Griselda Romney, her old owner. The impulsive Griselda, taking with her little Amabel and, of course, Nanny, sails for Egypt - to find Philomena and bring her home.