"Richard Roper" (Hugh Laurie) is extraordinarily charming for an arms dealer. He is well-educated and, at first glance, appears to be a distinguished billionaire businessman, philanthropist and gentleman. However, a look behind the polished exterior reveals an unscrupulous and merciless entrepreneur, who has amassed his fortune by the most despicable means possible, selling and buying weapons, trading in human life. In order to infiltrate his inner circle, "Jonathan Pine" saves "Roper's" son from being "abducted", in a carefully staged incident organised by intelligence officer, and "Pine's" handler, "Angela Burr" (Olivia Colman). A grateful "Roper" welcomes him into his inner circle, something that might prove to be a big mistake...