The escapers were going to make their way across Germany in a variety of disguises ranging from smart lawyers, accountants and doctors in petite bourgeoisie business suits, to foreign laborers and seamen in worn rags.

As March 23 approached, each rehearsed his cover story, studied maps and brushed up on their foreign languages. (Johnny had attempted to learn German intermittently during the years of his captivity, but could barely master more than a few incoherent phrases.) Some, perhaps, revised their plans. “There was a fever of excitement about the place,” recalls Jimmy James in his memoir Moonless Night. “None of the escapers seriously gave any thought to the consequences of recapture after a mass escape on this scale. In the same way that a pilot doesnt think about whether he’s going to be shot down before he climbs into his cockpit.”

Perhaps that was a credible state of mind for an English officer, but some of the other nationalities flying with the RAF had had many sleepless nights wondering what their fates might be if the Gestapo got its hands on them.

The escapers had been given dozens of talks about the various escape routes out of the camp, details of which were provided by those who had been out on parole, or by tame ferrets, or prisoners who had escaped. They knew that there was some sort of heavily guarded lighted compound near the camp that it would be preferable to avoid. There were several large and small towns near Sagan that would be best steered clear of: urban areas were far more extensively patrolled by the ever-vigilant Hitler Youth and the elderly Home Guard, and it was difficult to evade the unpredictable security checks at street corners.

The escapers knew that the Oder River was to the north of Sagan, and might provide a valuable means of escape; the Berlin-to-Breslau autobahn was to the south. Anyone planning to go to Switzerland was given a pep talk by Roger Bushell, drawing upon the unhappy experiences of his ill-fated escape bid in 1941. As the date of the break-out approached, a palpable sense of excitement filled the air and spread to the surrounding compounds.

The Senior American Officer, Albert “Bub” Clark, remembered there was a “buzz” about the camp for several days before the actual escape. This, surely, could not have escaped the notice of the German security staff, who were intimately familiar with every aspect of camp life.

Unfortunately, when the morning of March 23 dawned, a thick blanket of snow covered the compound. One of the prisoners, Leonard Hall, a member of the RAF meteorological branch, advised the escape committee to postpone the break-out for another day. He said that the next few days would be very cold but cloud cover would make the evenings very dark. That night, there was a heavy snowfall during a rehearsal of Pygmalion in the theatre. Roger Bushell was playing Professor Henry Higgins. The following morning the escape committee met and the decision to go was made. The forging department promptly began stamping the correct dates on scores of bogus papers.