My guest on this week's Book Club podcast is the award-winning novelist Colum McCann, whose new book takes him out of the territory of fiction and into something slightly different. American Mother is written in collaboration with Diane Foley, mother of Jim Foley, the journalist killed by ISIS in Syria in 2014. He tells me how he came to reinvent himself as (not quite) a ghostwriter, why he thinks you can use the tools of the fiction-writer to get at journalistic truth, and about what it was like to sit in the room with Diane Foley and the man who murdered her son.