Edward D. O'Connor's The Pentecostal Movement in the Catholic Church provides a concrete overview of the origins, development, and status of the Catholic Charismatic Movement. The book examines the phenomena of baptism in the Spirit, charisms (the gift of tongues), and prayer meetings through a theological approach and personal testimony. The author analyzes their impact on the Catholic tradition, balancing their spiritual benefits with their potential dangers, making this the definitive study of this spiritual revival. The book focuses on the lived experiences of the movement's participants and its place in the post-Vatican II Catholic Church.