The first part of the answer is easy: until life improves inthe Mexican countryside, there will always be migrants ready to undertake a perilous journey north.
They were built under the mandates of the Communist Party to provide jobs for the hundreds of thousands of people living thecountryside for a better lifeinthe cities, rather than to house genuine business tenants.
The book takes you on a journey with Hetty from her life with a foster family inthecountryside and back to the Foundling Hospital where she was left as a baby, in search of her real mother.
No one has much clue about conditions inthecountryside, but the direction of the refugee flow suggests that life there is even worse than inthe capital.