What do you get when you mix two serial killers with serious psychological kinks, an eclectic mix of art and art history, globetrotting, Scandinavian journalism and policing, and a desperate NYPD detective?

You get The Postcard Killers, a fast-paced joint venture between Alex Cross creator James Patterson and Swedish bestselling author Liza Marklund.

The killers earn the titular moniker from their ritual of sending a postcard of their next target city to a journalist or reporter in that city wi...