4. San Francisco - Eps 4

2018 - Season 3

3. San Francisco - Eps 3

2018 - Season 3

2. San Francisco - Wake

2018 - Season 3

The local police chief doesn’t take kindly to an English woman, Second World War code-cracker Millie (Rachael Stirling), presenting him with a list of possible killers and expects him just to get on with making an arrest. As the Circlers come up with the exact time, date and location of the next murder, they decide they must intervene.

1. San Francisco - Presidio

2018 - Season 3

Two of the original Code Breakers, Millie and Jean (Rachael Stirling and Julie Graham), arrive in San Francisco in 1956, 14 years after the murder of a colleague. They fear the killer has struck again, this time in the American city (he leaves a significant mark on his victims’ hands) and through a mixture of guilt and tenacity, decide to track him down. They are helped by an American codebreaker they worked with during the war.