Excellent article and interview with the two sons.

They do however maintain that their mother did no spying, although she was probably aware that her husband was an active spy. And they do maintain that the death penalty was too extreme a punishment for the actual spying that was done.

It's probably more difficult too judge this crime in the context of the time. In our time major international spies are routinely swapped after a brief time in prison.

Charley Noble