Which C.S. Lewis work was published under the pen name N.W. Clerk?

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

Lewis wrote A Grief Observed after the death of his wife, Joy Davidman, from cancer in 1960. The book records his changing emotions, doubts and reflections on bereavement in a direct, journal-like form. It first appeared in 1961 under the pseudonym N.W. Clerk.

Lewis used the pseudonym partly to keep readers from treating the book as an official statement by a famous Christian author. After his death, the work was republished under his name, and it became widely known as one of the most candid accounts of grief in modern Christian literature.

The book is sometimes confused with Surprised by Joy, Lewis’s earlier autobiography. That work describes his intellectual and spiritual development, whereas A Grief Observed focuses on the experience of mourning after Davidman’s death.