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, 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?

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 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.