Nick Turnhouse is a Dorset farmhand, a third son with nothing to inherit and no future, working his father's land for his keep. He is also tall, powerfully built, and handsome, and crosses the path of Squire's impressionable daughter.
Nick has to run, fast, with ten shillings and his father's blessing. Luckily, or so he thinks, he comes across a kind gentleman who can help him. After Nick is persuaded to say that he is looking for work, he discovers the man is recruiting for the Navy, and Nick has just 'volunteered in fact'.
Once at sea, he is amazed to discover that he is not stupid - he has simply had no occasion to use his brain plodding on the farm. He can learn and fight, and wishes to do both, finding his chance to rise in the nautical world.