Location: The Florida Everglades, United StatesDebbie and Eliza explore the Everglades but drop Nigel's birthday present, a new watch, into the swamp. As an old woman chases them away, they return at night, only to have the watch eaten by an alligator.

Location: The border of Oaxala and Zaachula, MexicoAs the family prepares to film the ""Day of the Dead"" ceremony in a small town, Eliza meets a little girl who tells her about the spirits returning. Eliza is determined to find one, but when Donnie puts a vaulable ring in a loaf of bread, Debbie and Eliza must search for the missing ring. Eliza gets some help from a mysterious woman who, she finds out, has been gone for many years.

Location: Lake Baikal, SiberiaWhen Eliza and Debbie slack off on their chores, they all suffer for it when they fail to prepare of an oncoming storm. Will the Thornberrys survive a flash flood, help some beavers build their dam and keep the Comvee from sinking?

Location: Alice Springs, AustraliaDebbie is finally going to meet her e-mail friend in person and she is determined to make a good impression. Meanwhile, Eliza is having strange pains in her stomach and ends up stranded on top of a small mountain as Donnie gets attacked by a giant eagle. Just a typical Valentine's Day for the Thornberrys in Australia.

Location: Shark Bay, AustraliaNigel and Marianne are on a dangerous assignment to film some tiger sharks while Eliza goes swimming with some dolphins. Meanwhile, Debbie gets dumped by her e-mail boyfriend Sven. When the kids take a boat out with the dolphins to swim in the deep sea, they may get some unexpected visitors.

Location: Rotura, New ZealandThe Thornberrys visit a tribe of native New Zealanders called the Mahris who are throwing a celebration called a ""Hooey"". As Debbie flirts with a young Mahri, Eliza and Darwin have a fight. When Darwin leaves and Eliza befriends a possum named Penelope who ends up getting her into a hot air balloon that she doesn't know how to steer, will Darwin come to the rescue?

Location: Ha Long Bay, VietnamEliza encounters a mysterious creature while shooting a film with Nigel about manta rays.

Location: Borneo, IndonesiaThe Thornberrys reunite and find Donnie in a remote village and learn from the medicine woman there the terrible fate that befell his parents.

Location: Borneo, IndonesiaA huge fire strikes while Eliza and Darwin search for Donnie, Nigel and Marianne come across poachers, and Debbie and Grandma Sophie get taken in by a native tribe.

A trip to the Great Wall of China finds Eliza in hot pursuit of a panda and his mother.

Location: Mt. KilimanjaroTo celebrate his 13th birthday, Tyler and Eliza visit a pair of elephants in the African savanna.

Location: Ankarana, MadagascarThe Thornberrys are preparing for Thanksgiving in Madagascar when Grandma Sophie calls, inviting them home for the holiday. When Nigel and Marianne explain that they can't go home until they get footage of a fossa for The Foundation, Debbie throws a tantrum. Will the girls, Donnie, and Darwin go to the states on their own when tradition has always had the Thornberry clan together on Thanksgiving?

Location: BhutanA trip to Bhutan, finds Marianne and Debbie out in the cold, and Eliza and Darwin on the run from the border police.

Location: Borneo, IndonesiaThe Thornberrys are preparing for Donnie's ""birthday"" party in Borneo when one crisis after another happens. Grandma Sophie decides to visit the same day Nigel and Marianne must capture a wild orangutan on film or the foundation will cut their funding.

Location: Borneo, IndonesiaDonnie searches the jungles of Borneo for his ancestry, causing Eliza to worry that he will break ties with the Thornberry clan.

Location: The Siwa Oasis, EgyptEliza challenges Tyler to lead the group to safety after they land in an underground burial chamber.

Mt. Fuji, JapanGrandpa Frank marks the occasion of his 50th wedding anniversary by throwing caution to the wind and joining Eliza on a rigorous mountain climb.

Eliza's cousin Tyler Tucker joins the Thornberrys for a four-week tour from Africa to the Amazon in search of exotic, endangered and mysterious animals.

Location: Kakadu National Park, Northern Territory, AustraliaThe Thornberrys meet an Australian family named the Gibsons when the Comvee runs out of gas. Eliza makes friends with the youngest member of the family named Bethany, who is in a wheelchair from cerebal palsy. The girls go land sailing and Bethany helps Eliza escape from a crocodile, but then get in an arguement when Bethany thinks Eliza is feeling sorry for her being disabled. Will the two new friends find a way to make up? Meanwhile, Nigel and Marianne play the Gibsons in a very competitive game of Tricky Trivia.

Eliza and Debbie embark on a dangerous trek in search of precious gemstones.

In the hope of winning the annual horse race, Eliza trades in her bungling trotter for a swift Thoroughbred.

Location: Zanzibar, TanzaniaDebbie and Tyler mistakenly trade the commvee for a dress at an island marketplace; Marianne and Nigel explore the Ngorongoro Crater.

Location: Okavango Swamp, BotswanaIt's April Fools day, and The Thornberrys are trying to outdo each other by way of April Fool's jokes. At first it's a lot of fun, but when Tyler and Eliza encounter some quicksand and a lion, will they learn not to cry wolf? Meanwhile, Nigel coaches Debbie for her Physical Education courses.

Location: Masai Steppe, TanzaniaEliza and Tyler work together to help an aspiring Masai warrior earn the respect of his elders.

Location: Quito, EcuadorBefore New Year's Eve, Debbie accidentally hurts fer father's feelings, and joins a couple of eccentric, 30's-era volcano chasers, Mitzi and Merrick Dash. Eliza goes after her to reclaim her friend, Santusa the Llama, and they all encounter a mudslide when the volcano erupts.