The outsider is a perpetual theme in literature. In Ishiguro's best-known novel The Remains of the Day it was the butler, forever cut off from the lower servants by his higher status, and separated by an even wider gulf from the employers he so slavishly imitated, writes Chris Gray.

In Ishiguro's new novel the orphans are Christopher Banks, whose parents both disappeared in turn-of-the-century Shanghai, and Sarah Hemmings, an orphan who attempts to replace her lost parents by engaging in a lifelong search for a man who will achieve something worthwhile in the world.

Banks has become a detective in the hope both of finding his parents and of ridding the world of evil. The story begins in the pedantic style so beloved of Sherlock Holmes and includes the comforting conventions of the crime genre. Ishiguro cannot resist straying into the surreal at times, but this book, having a quite discernible plot, is much more accessible than his previous novel The Unconsoled. Although the story is totally gripping at times, Ishiguro transcends the limitations of the detective genre to reflect not only on loneliness and how profoundly people are affected by the loss of sense of belonging, but also how our beliefs affect the way we live our lives.