The Morning Gift- Eva Ibbotson

Ruth lives in Vienna and is wildly in love with Heini Radik, a brilliant young pianist. When Hitler's forces invade Ruth's family flees to London, but she cannot get a passport. Quin, a young professor and friend of the family, visits Ruth and offers a marriage of convenience. On their return to London, Quin begins to fall desperately in love with her. But then Heini turns up…