In his clumsiness, Sir Thornberry inadvertently releases the Spinster, an old menace of the Gummi Bears, and now he is his friends' best hope of escaping this monster before it makes dinner out of them.

With no sign of Igthorn for an entire year, not even in his own castle, Zummi Gummi finds this news as a perfect opportunity to call on the Great Gummies (much to the skepticism of Gruffi). However, Igthorn has recently devised the ultimate plan to finally capture the Gummies, obtain the Gummiberry juice, and take over Dunwyn.

Igthorn and his ogres have destroyed Gummi Glen, captured Dunwyn Kingdom and its citizens, and are keeping Grammi and Tummi held in Drekmore. Now Cavin and the remaining Gummies, with the help of the Barbics, must save them all while Zummi retrieves the Great Book and warn the Great Gummies to turn back.

While thwarting yet one more attempt of Igthorn to claim rulership, Sir Tuxford is injured, so Sir Victor is called in to defend Dunwyn for the period of Tuxford's recovery. However, soon Igthorn hits upon a plan to use his likeness to his twin brother to conquer Dunwyn after all ...

Eager to meet the Barbics, Cavin accompanies the Gummis on a trip to Ursalia. He is at first not welcomed by the Barbics, but soon gets the chance to prove himself in a manhood ritual which Buddy has to undergo in order to become a full member of his tribe. However, a pair of satyr poachers are on the prowl looking for furs to line their purses – and the Gummis just so happen to be quite hairy ...