Directed by Edward Hall, the film features Hayley Atwell, Rufus Sewell, Michelle Dockery, Michael Gambon and Charlotte Rampling.

The first episode opens in the 1970s with Ruth Gilmartin, a PhD student at St John's College, Cambridge, driving with her young son to visit her mother in her country cottage.

Eva is sent to the United States as part of a team which uses misinformation and news stories to encourage the U.S. government to support the British war effort.

She is ordered by Lucas to seduce the married Mason Harding, an adviser to the president, ostensibly to find out if the Americans intend on joining the war, but actually to blackmail him.

A second assignment is to supply a map to American agents supposedly outlining a planned German invasion of the United States via Mexico.

After Eva survives an attempt to kill her in the desert, through serendipitous circumstances the map makes its way to and fools the U.S. president, Roosevelt, as to German intentions.

Adrian Michaels, writing for The Daily Telegraph, praised the first part of the adaptation as "terrific", saying: "There was enough plot development to keep everything ticking along, but at an easy pace that was a welcome change from Scandinavian psychopaths starting a bloodbath every 15 minutes.

"[2] The first part was also received well by John Crace in The Guardian; he commented on the high production values and compared it to another series featuring Dockery, saying it "was everything [Downton Abbey] isn't: well-acted, well-written, well-paced and well-filmed".