How would David be able to escape the concentration camp?

The commandant helped David. He made sure that he had access to food and vitamins and one day, inexplicably, set up his escape. He hid a get-away bag outside the fence and turned of the electric current in the fence momentarily, so that David could escape. He told David to head for Salonika in the south and take a boat to Italy from there. He should then head to Denmark.