1803-1804: Uncertain peace reigns between England and France. Richard Delancey, RN, is ashore, but conflict still abounds. He forms an attachment for the pretty actress Fiona that threatens his career - and mixes with men of the Opposition Party.
Then war breaks out again. Napoleon's first move is to invade England, and rumours circulate of steam-driven ships and a warcraft that can travel under the water.
Delancey's courage and skill are called upon for the most audacious adventure of his career.