I did not get on well with the only other Doris Lessing book I have read, The Grass is Singing, but I thought this was excellent - a short novel about a woman in her mid-40s who suddenly gets an opportunity to break away from her family and friends, and grabs it with both hands. I found the geographical and character descriptions excellent, and Kate's journey to freedom rather exhilarating. Recommended.
(Yes, I know that icon is Agatha Christie. Sorry.)