Watched this as a kid and then a few years ago, and am now binge watching again. After the first 3 parts that get the men to Colditz, this is one of the finest things the BBC ever did. The acting throughout is quite brilliant, with the passing of time - so hard to capture - superbly done. The exchanges between Jack Hedley and Bernard Hepton are some of the finest in the history of British TV.
Review of Colditz
