Briar and Bramble, the two bear brothers always getting in Vick's way, are in for a rude awakening. Vick heads out to shrink them out of his life. In the tussle the device is tossed and all three of them are caught in the beam and find themselves looking up at the rest of the world. The tiny team have to get back to the device to reverse the effects but their efforts are intercepted by Vick's dad. He comes back to apologize to Vick but leaves with the machine when he can't find him. The three now go on a wild chase through a magnificent world just underneath our feet to not only restore their size, but to restore family.