This book is a follow up to "The Kommandant's Girl" and has many of the same characters. Luckily the author did a good job of referencing what happened to Marta in the previous book. If I recall correctly, Marta was kind of a secondary character to Emma (who was the title character).

Marta ends up in London working for the British Intelligence Agency, which is comparable to the CIA in the US. Once her supervisor (the DM) finds out about her past with the Polish Resistance, she gets a top secret mission where she re-visits her past. Of course, most of what actually ends up happening is highly unlikely, but it is an enjoyable novel about post-war Britain and the fight against communism from a different perspective. I look forward to reading Book #3 in the series.