In this slim book, written shortly before his death, C. S. Lewis explores the subject of prayer. Lewis presents the material as a series of letters to an imaginary correspondent called "Malcolm". This device is effective in creating a sense of intimacy; one has the feeling that Lewis is being touchingly frank in his discussion of the difficulties and rewards of the Christian life in general, and prayer in particular. He has interesting and useful things to say about all aspects of prayer: the petitionary prayer, prayers of praise, corporate prayer, and whether it is right to pray for the dead. Lewis's theology has not changed significantly since his much earlier books Mere Christianity and The Screwtape Letters, yet there is something mellower and less confrontational in this writing than in Lewis's more famous Christian books, and it is all the more moving and persuasive for it. The fact that this book was written so near to Lewis's premature death gives it an added poignancy. In conclusion, this is a first rate book which deserves to be more widely known.