Midshipman Plunkett Timeline and Summary

Back in the 18th century… Major Plunkett's ancestor rides in a coach through the Dutch countryside.
He's heading toward the seacoast to do some spying for the British since the Dutch are suspected of aiding the French (who are aiding the Americans) in the Revolutionary War.
At the port, he hides among the cargo to make his observations. It's touch and go, but he makes it out and his intelligence is useful.
We next see Midshipman Plunkett below decks on The Marlborough, Admiral Rodney's warship, in the middle of the Battle of the Saints.
Through a series of unfortunate maneuvers, Plunkett accidentally impales himself on his own sword. To add insult to fatal injury, he drowns in the waters pouring through the hull.
Midshipman Plunkett is "resurrected" in the 20th century when his relative, Major Plunkett, discovers his name through his research.
The Major "adopts" him as a son and tries to reconstruct the young man's experience on the island.
On his return trip across the bottom of the sea floor—and through the centuries—Achille witnesses Midshipman Plunkett's drowning.