Which C.S. Lewis book was originally published under the name N.W. Clerk?

A Grief Observed was originally published under the name N.W. Clerk.

C.S. Lewis used the pseudonym N.W. Clerk when the book first appeared in 1961. It records his intense grief and spiritual questioning after the death of his wife, Joy Davidman, from cancer in 1960.

The book is written as a series of reflections rather than as a conventional biography of Davidman. Lewis examines anger, doubt, loneliness, and the difficulty of reconciling suffering with belief. The pseudonym initially helped create distance between the private experience and the author’s public reputation; later editions identified Lewis as the author.