Ducky is upset with her brother Spike, for keeping her awake at night with his snoring (called "sleep rumbling" by the characters), and for eating her treestars. She tells Cera about her feelings, and confides that she does not know how to express them, to which Cera agrees to teach her. At the same time, the children are attending a school of sorts, in which they are taught by an old Pachyrhinosaurus named Mr. Thicknose, who professes to have been everywhere and seen everything. Littlefoot is eagerly questioning all the topics they cover, to the old dinosaur's irritation, and blows the top when he startles Mr. Thicknose into running into a tree, upon which a melon falls on his head. Mr. Thicknose complains to Grandpa Longneck about Littlefoot's behaviour, and Grandpa Longneck, knowing Littlefoot meant no harm, gently explains to him why he must be more respectful to Mr. Thicknose.
Meanwhile, as Ducky gives Spike the cold shoulder, Spike meets and befriends a boy from a wandering Spiketail herd, who have recently arrived in the Great Valley. Ducky begins to miss Spike, as she watches him spend more and more time with this herd of his own species. One day, however, the entire Valley is surprised by an overnight snowfall (which the characters refer to as either "white sky sparkles" or "white ground sparkles"). While the children together have fun frolicking in the snow, the adults complain that Mr. Thicknose did not warn them about this sort of thing happening in the Valley, and suspect that he does not know as much as he claims.
As time wears on, the dinosaurs begin to notice the more horrific side to snowfall; the freezing temperatures and the lack of food growth. The spiketail herd offers to leave, as they consume more food than most species. The mother of Spike's new friend, Tippy, asks Mama Swimmer if she can take Spike along during the cold time, and Mama Swimmer decides that Spike should choose between staying in the valley, or leaving with them. Spike is unsure, so Ducky frustratedly tells him to go off. As he leaves, she immediately regrets her actions, and later sneaks away to follow the spiketail herd. When her friends find this out, they head off into the Mysterious Beyond to find her, but are interrupted by Mr. Thicknose, who tells them he will not let them go off there by themselves, and leaves with them. After several rough scrapes, including a chase from a mountain sharptooth, and successfully finding Ducky, they come across a frozen pool of water, which they break by accident. Underneath the ice is warm water, and they notice that there is lush food nearby. While they relax in the water and feed, Mr. Thicknose confesses that most of his knowledge comes from secondary sources; he listened to the stories of the grownup travelers when he was a child, and in his adult years, he told those stories to the children in the valley.
Later, the group tries to contact the residents of the valley, to let them know about the safe haven they have found, but find that a snowfall has blocked them off from the valley. Ducky, remembering what Cera taught her, suggests that Cera get angry and riled up at the ground sparkles. Cera does so, and her enraged screaming causes the wall of snow to fall down, enabling the rest of the Great Valley herd to pass through. Meanwhile, the Spiketail herd is starving, until Spike picks up the scent of the location the valley residents are in. He leads the spiketails there, and reunites with Ducky. However, after a few minutes, he falls into a deep part of the water, and as he is unable to swim, Mama Swimmer jumps in to save him. When she places him on dry ground again, Tippy's mother says that Spike should stay with his family, rather than her herd. Ducky promises to Spike that she will not get angry at him whenever he snores, ever again.
- Thomas Dekker - Littlefoot
- Anndi McAfee - Cera
- Aria Curzon - Ducky
- Jeff Bennett - Petrie / Corythosaurus
- Rob Paulsen - Spike / Leading Stegosaurus
- Tress MacNeille - Ducky's Mom / Petrie's Mom
- Susan Krebs - Tippy's Mom / Ankylosaurus
- Jeremy Suarez - Tippy
- Robert Guillaume - Mr. Thicknose
- Kenneth Mars - Grandpa Longneck
- Miriam Flynn - Grandma Longneck
- John Ingle - Narrator / Topsy
- Jim Cummings - Lambeosaurus (uncredited)
- The Mad Song - Cera and Ducky (Anndi McAfee and Aria Noelle Curzon)
- Family - Ducky, Ducky's Mother, Littlefoot, Cera and Petrie (Aria Noelle Curzon, Tress MacNeille, Thomas Dekker, Anndi McAfee and Jeff Bennett)
- The Lesson - Mr. Thicknose, Littlefoot, Cera, Ducky and Petrie (Robert Guillaume, Thomas Dekker, Anndi McAfee, Aria Noelle Curzon and Jeff Bennett)
"If We Hold On Together" (instrumental)
Home video release historyEdit
- December 4, 2001 (VHS and DVD)
- December 2, 2003 (VHS and DVD - 4 Movie Dino Pack (Volume 2) and 9 Movie Dino Pack)
- February 7, 2006 (DVD - 2 Dino-Riffic Adventures)
- August 5, 2008 (Carrying Case DVD with Fun Activity Book - 2 Dino-Riffic Adventures - Universal Watch on the Go)