When the kids narrowly escape the destruction of an island, they discover the true cause of it in the form of an evil captain and his new, advanced submarine. When they journey to the Arctic, they're going to need as much help as possible to stop his wicked plans of using it to conquer the world. Will their appeals to snow creatures and the captain's primitive assistant lead to their salvation?

In an African jungle, Tom is stung by a poisonous plant and it's up to Huck and Becky to find an antidote for him. Though they find a trade ship that has the medicine, it holds a secret that may lead to doom for all three kids if they don't act in time to save Tom.

Tom, Huck, and Becky meet the legendary Don Quixote and Sancho Panza, but the adventure is just beginning when Sancho is kidnapped and the kids have to help Don rescue him in whatever unusual way they can. As confused as Quixote is, they're definitely going to need some big help as he and Tom are imprisoned with Sancho as well.

Utilizing a hot air balloon, Huck, Becky, and Tom attempt to get back to Hannibal, Missouri. But they wind up in a valley full of warring cavemen. Huck is separated from the others and found by one group of primitives while Tom and Becky wind up meeting another. As the two groups battle, Tom and Huck make things worse by helping their respective group better battle each other by introducing more advanced weapons to them. Can Becky stop them from going too far, or will another primitive tribe get the upper hand as a result of their interference?

Tom, Huck, and Becky find themselves near an old medieval castle where it's been taken over by an evil wizard. After he captures and imprisons Becky, the boys have to rely on their wits and some luck to make their way into and through the castle in order to rescue her and a princess. Will they succeed or will the evil wizard cast his magic upon them all and come out the victor?

In Ireland, Becky meets a group of Leprechauns who have trouble hiding their prescious magic shillelagh, the source of all their power. When gypsies seek this power and kidnap Tom and Huck in the process, Becky must work with the Leprechauns to keep the shillelagh out of the wrong hands and save the boys from peril.

When the kids save a young maiden from sacrifice to a dragon, they get in big trouble by the Guru of New Olympus. They themselves are slated to be a meal for a moat monster, but escape with some help. They need to save the maiden again and must go on a perilous mission to do so. Will they succeed, or will their fate be set in stone?

The kids are in for a surprise when they travel to an island that's inhabited by quite unusual animals. They all have to deal with a hunter who seeks to add a few trophies to his collection. Can the kids and the animals work together to stop him?

While exploring an ancient Aztec temple, Tom becomes revered as its people's sun king. But is there more to this than being treated as royalty? It's up to Huck and Becky to save him from himself as they learn the truth as to what's really going on.

After the kids encounter an obsessed sea captain, they find themselves in a real-life Moby Dick-style adventure as they have to decide what is worse; getting hunted down by him, or having to make their way inside the whale that he so covets most?

Huck, Tom, and Becky find gold in an old Incan palace in Peru, but this gold bears a curse that could jeopardize their friendship. Will the boys' greed get the better of them as they begin battling over the gold?

After Becky is kidnapped by a ruthless ruler, it's up to Huck and Tom to rescue her. Because they're on a land where magic is used on a regular basis, they'll need some special help of their own from a friendly wizard as well as their wits in order to save Becky from a terrible fate.

Seeking shelter from wolves in a nearby forest, Becky, Tom, and Huck are invited into a scientist's house where his hospitality turns into his own personal science project as he demonstrates his latest invention to them. It's a miniturization machine which he successfully used on a dog. But to prove its full potential, he needs a human subject. Huck becomes his unfortunate victim and in front of the others, is shrunken down to a mere 10 centimeters (4 inches). It's up to Tom, Becky, and the dog to get Huck back to normal size. But will another one of the scientist's experiments lead to their doom?

Tom, Huck, and Becky, meet the legendary demigod Hercules in ancient Greece. But things aren't all that friendly as evil king Hades tries to do what he can to stop him from completing his great 12 labors. Things get worse for the kids as they're accused by Hercules himself of attemping to sabotage his labors and become imprisoned in Hades' high-tower prison as a result. Can the kids escape in time to clear their names and warn the demigod of the evil king's true intentions?

Tom, Huck, and Becky are in Egypt where they encounter a mummy, as well as thieves who are using him to steal valuable pyramid treasures. When they're captured by the latter, will they be able to escape their own entombment?

Tom, Huck, and Becky arrive in China and save a young prince from being ambushed by Mongol bandits. They however, are captured by the rogues and Tom is forced to help them find a way into the kingdom of Petchu so the bandits can loot and conquer it. With Huck and Becky as their hostages, he has little choice but to comply. The task proves even more difficult when the people of Petchu revere him as the divine one who saved the prince from capture and is held against his will, which will lead to his friends' doom unless he finds a way to escape.

In their first great adventure, Huckleberry Finn, Tom Sawyer, and Becky Thatcher visit a valley where they witness the theft of a powerful gem from an idol that the natives worship. The boys wind up becoming responsible for its safe return after being initially accused of stealing it. With Becky as the natives' hostage, they have a short time to get the gem back before she's sacrificed. Will Tom and Huck overcome the odds against the thugs and save Becky in time?

Rest and relaxation on a tropical island turns into a grand adventure when the kids encounter gorillas, pirates and excitement aboard their ship after the latter capture Tom and Becky. Can Huck rescue them in time or will they all be casualties to the cutthroats?

When the kids wind up on an island after a fierce storm, Huck finds himself in the role of Gulliver to the small people of Lilliput. Needing a big protector for their community, the king forces him into a vow of marriage to his daughter hoping he'll be their permanent guardian. But will a lovesick Lilliputian and a new threat to the island be too much for him to handle?

Huck, Tom, and Becky are in for a grand adventure as they wind up in the undersea world of Atlantis. There, they meet a young king who switches clothes with Huck and causes a little confusion as the latter is captured by a familiar-looking person who seeks to overthrow the king. Will the kids be able to help the king before it's too late?