some guesses on what's what and what's going to happen
The maid, Anna, who is engaged to Dieter is a spy for MI19.
Charlotte Riley is a Russian spy trying to snare Dieter for the Russians.
Angela Bassett may be working for the CIA, or equivalent at the time.
Cam's brother is going mad and will try to kill Dieter but end up killing his daughter by mistake.
Alfred Molina was present at the meeting in 1938 where the Wehrmacht's offer was rejected. He wants to atone for his mistake and take the others present at the meeting down with him.
You're my wife now.