2020 brings readers the 400th anniversary of the sailing of the Mayflower<U+2015>the ship that took the Pilgrim Fathers to the New World. It is a foundational event in American history, but it began as an English story, which pioneered the idea of religious freedom. The illegal underground movement of Protestant separatists from Elizabeth I<U+2019>s Church of England is a story of subterfuge and danger, arrests and interrogations, prison and executions. It starts with Queen Mary<U+2019>s attempts to burn Protestantism out of England, which created a Protestant underground. Later, when Elizabeth<U+2019>s Protestant reformation didn<U+2019>t go far enough, radicals recreated that underground, meeting illegally throughout England, facing prison and death for their crimes. They went into exile in the Netherlands, where they lived in poverty<U+2015>and finally to the New World. Historian Stephen Tomkins tells this fascinating story<U+2015>one that is rarely told as an important piece of English, as well as American, history<U+2015>that is full of contemporary relevance: religious violence, the threat to national security, freedom of religion, and tolerance of dangerous opinions.