Survival
The overarching theme of this book is that of survival. In fact, the title of this text contributes to this theme. The central idea is that, despite all the obstacles that are thrown their way, the passengers manage to survive.
Hardships
One of the peripheral themes in the context of this text is that of hardships. The passengers are faced with a number of obstacles and they are doomed to fight them to make it back; indeed, hardships play an important role in their lives.
Resilience
Another very important theme that figures in this text. This text is a constant reminder that one can overcome anything with a bit of resilience. With barely any food in their systems, will was all they had.
Faith
Faith is another important theme. It is very important in the context of this text because by the end, due to their strange experience, the faith of the passengers is restored, and thus faith becomes an important topic for the author to talk about.