Blood on Their Hands (1) (S02E01)

Alice Merren, a former employee at Bletchley Park, finds herself in jail as she awaits trial for the murder of renowned scientist John Richards. Convinced of Alice's innocence and sensing that she knows more about John's demise than she's letting on, Jean sets out to rally their old team. Her goal is to uncover the truth and prove that one of their own is not guilty of this crime.