Every week, in small groups across the country, thousands of agnostics - complete strangers - gather to find out more about Christianity. They're on the Alpha course, the phenomenonally successful introduction to Christianity which converts the faithless into committed Christians on an industrial scale. With 100% access Jon Ronson follows one small Alpha group, documenting the whole process over its eight weeks. Will any of the members of the group convert to Christianity by the end of the course?