LitCharts assigns a color and icon to each theme in Mortal Engines, which you can use to track the themes throughout the work.
Social Class
Sacrifice
Dangers of Technology
The Importance of History
Prejudice and First Impressions
Friendship
Summary
Analysis
After a rainy night in London, the air clears, and that morning, it’s time for Valentine to leave. Katherine and Dog wish Valentine goodbye, along with a crowd of other people, including Crome. His ship takes off, and Katherine starts crying. While Valentine is gone, she plans to find out more about the mysterious girl (Hester) who seemed to scare her father so much.
Much of the middle of the book shifts perspective between London and Tom and Hester’s adventures abroad. Katherine doesn’t understand much of what she sees in London, but she is able to put together bits and pieces of what Crome has planned for the future.