Dr Ragab's Universal Language

Charlatan. Guru. Master of disguise. Ahead of his time, wise beyond his years, a simple opportunist or the great pretender; however you choose to see him, one fact is certain: Dr Ragab is a mysterious man. Talked about by pretty much everyone in 1920s Cairo, only a few get the chance to make his acquaintance, and fewer still -- one person, in fact -- get to study his life lessons. Hertwig is that lucky soul.
Or not so lucky, perhaps: not when he finds himself, at the very end of the second world war, imprisoned in a bunker in Germany by a gang of thugs. To make matters worse, it's not just any bunker; it's the family bunker, built to be 100% escape-proof. And yet .