London, 1798. Born into poverty, illiterate, eighteen-year-old Sarah Evans has been raised to believe she has no rights at all. She and her childhood friend, Lucy Burnes, struggle daily to find food and shelter, drawing strength and comfort from their friendship.

When she is falsely accused and found guilty of theft, Sarah is sentenced to transportation, but, instead, she is secretly transferred to Coldbath Fields, one of London's most notorious prisons, at the request of its sadistic governor, Thomas Aris. Placed in his household, she becomes entangled in a web of sexual exploitation, cruelty and corruption, where powerful men rule and the law disregards women.

When Sarah is presented with an opportunity to regain her freedom, she seizes it. But even beyond the prison walls, she discovers she cannot escape Aris's control over herself and her children.

She can no longer turn to Lucy for support - her friend is a convict in New South Wales, her life's journey taking her down a path as hopeful as Sarah's is desperate. Instead, she finds kindness and protection among the network of women who, like her, are struggling to avoid starvation on the pitiless streets of London. At the lowest point of her life - accused of murder and facing the death penalty - these strong women don't let her down.

And Sarah is a force in her own right. Drawn into a circle of political rebels, she is introduced to the concepts of justice and equality. Despite the brutal challenges that life throws at her, she learns her own value and begins to fight for her rights.

In the end, it is the power of thoughts and words that shapes Sarah Evans's life, not the hardship she has known. And it is friendship that teaches her the most important kind of freedom: liberty of mind.