Which 1956 novel was the last fiction book C.S. Lewis completed?

Till We Have Faces was the last fiction book C.S. Lewis completed, published in 1956. Lewis described it as a retelling of the ancient myth of Cupid and Psyche.

The novel is narrated primarily by Orual, a queen whose relationship with her half-sister Psyche drives the story. Lewis relocates the myth to the fictional kingdom of Glome and gives the narrator a psychologically complex voice shaped by jealousy, love, grief, and self-justification.

Lewis co-wrote the book's dedication to Joy Davidman, whom he married that year. He considered the novel one of his most fully realized works, although it was less immediately popular than the Narnia books.

The Last Battle is also associated with Lewis's final years because it concluded The Chronicles of Narnia in 1956. It was not, however, the last fiction book he completed: Till We Have Faces was published later in that same year.