Jack and Emilia meet Croque and Brogard on the beach and learn that another ship has fallen victim to a supposed sea monster. Since this is the third ship to sink in one week, Emilia decides the matter warrants further investigation. She and Jack head out to sea in her submarine and come under the attack of a giant metallic shark. They are swallowed by the creature and find themselves inside a huge submarine. Jack and Emilia hide in an empty ballast pod while Captain Nardo da Vinci searches their sub. After he leaves, they exit their vessel and find the dreaded pirate Blackbeard locked in a cell. He doesn't recognize Jack and Emilia and tells them that he found himself to be Captain Nardo's prisoner after his ship sank, and is only allowed out of his cell to swab the deck.

Emilia figures that Blackbeard must know his way around the vessel by now and decides to free him. The trio make their way to the bridge of the sub and are cornered by Captain Nardo and his men. They learn that Nardo is the great, great, great, great grandson of Leonardo da Vinci and find that he obviously has issues with just how great Leonardo was. Captain Nardo reveals that he has built a torpedo and intends to demonstrate it in three days when the 'Founding Father/Son Cruise' passes through the East Indies. Jack is horrified when he thinks that such men as Washington, Jefferson, Franklin and Adams will be murdered so that Captain Nardo can become more famous than Leonardo.

Jack, Emilia and Blackbeard make a run for it and barricade themselves inside the torpedo room. Just as Nardo's men are about to burst through the door, all three launch themselves off the sub through the torpedo shoot. Later, they make their way out of the surf and devise a plan to defeat Nardo. Emilia builds a hot air balloon and the three take to the sky to search for Nardo's vessel. They spot his sub skimming beneath the surface of the ocean and Blackbeard drops a cannonball on it. Nardo realizes he has company and fires torpedoes at the balloon. A dud missile lodges in the balloon's basket and they start to sink.

Blackbeard blows fireballs to keep them afloat, but he suddenly recognizes Jack and Emilia to be the ones who previously sank his ship, and recognizes Jack as the Daring Dragoon. Blackbeard and the torpedo fall through the basket floor and crash into Nardo's sub with a giant explosion. Jack and Emilia return home, but unbeknownst to them, both Blackbeard and Captain Nardo escape certain death in Emilia's sub.

Starring: Bruce Campbell (Jack Stiles), Angela Dotchin (Emilia Rothschild), Stuart Devenie (Governor Croque), Stephen Papps (Captain Brogard), Shemp Wooley (The Voice of Jean-Claude)

Guest Stars: Michael Hurst (Captain Nardo da Vinci), Hori Ahipene (Blackbeard), Mark Williams (Sailor), Marek Summich (Survivor/Woody), Charles Pierard (Thomas Jefferson), Alistair Browning (George Washington), Patrick Morrison (Jefferson Jnr), Nicko Vella (Washington Jnr), Bruce Hopkins (Captain Standish)

Written by David Ransil
Directed by Eric Gruendemann