Liverpool 1792. The press-gang hauls its final recruit from the dockland inns and the Blackamoor Jenny embarks on another voyage on the high tide of British naval adventure with its cargo of African slaves.

Back home, the politicians manoeuvre for position on the slavery issue as the crew, ravaged by violent storms and total blindness, confront the rhythmic power of the sea. The exhilarating mixture of sea shanties, debate and personal conflict paint a vivid portrait of Britain then and now, on the scale of Moby Dick.