 Joining the gang, he learns of their plans, which he immediately leaks to his best friend and former partner Pat Flanagan and news reporter girlfriend Jean Ashley and, as "The Black Commando", continually frustrates the Nazi plots.After innumerable dangers and lost efforts in trying to decipher the enemy's secret codes, Barton and Flanagan discover the key to the Nazi code, capture the Nazi ring and make sure that the Nazi U-boat which has been waiting to help the Nazis escape is depth-bombed and destroyed.At the end of each episode, the audience is given a short lecture on solving complex secret messages.