The final episode was perhaps the best one for me both on the dramatic as well on the emotional side. Rosie's discovery of a forced labor camp packs a punch ( but not as brutal as BoB's discovery of an actual concentration camp), the 100th final "bomb" run to deliver supplies to their former enemies, prisoners being forced marched from place to place until they are finally rescued.
The supplies were being delivered to the Dutch in Nazi occupied Netherlands (UK and US ally) invaded by Germany.
Robert Rosenthal's walk around the camp is probably what influenced his decision to join the prosecution team at the Nuremberg Trials after the war.