The Grand Mountain Adventure Challenge is an annual contest for kids. The Challenge tests kids' abilities in canoeing, hiking, rock climbing and orienteering - and this year it has a 10,000 dollar prize. The unprincipled coach of one team kidnaps Lassie in hopes of taking Zoe and Harvey out of the race, but he has underestimated the kids' friendship with the other competitors, who join in the search for Lassie. And he has also severely underestimated Lassie's own resourcefulness and ability to escape. Zoe, Harvey and Lassie return to the starting line just in time to begin the race.