A 2-part miniseries, based on the bestselling novel by William Boyd. Enter a cloak and dagger world where everyone and everything is under suspicion. Haunted by the death of her brother at the hands of fascist thugs, Russian émigré Eva Delectorskaya is recruited to be a British secret agent by the shadowy figure, Lucas Romer. After proving her merit in the field, she is sent on the most dangerous mission of her life. She must use any means necessary...

This final series sees the Doc making efforts to overcome his phobia and beginning to question whether he made the right decision about resigning. He and Louisa have also welcomed a baby daughter, Mary Elizabeth, a sister to four-year-old James Henry; includes the feature-length finale special.