On the brink of perfecting his state-of-the-art matter-shrinking machine, the suburban paterfamilias and indefatigable inventor, Professor Wayne Szalinski, realises that his device truly works, when it zaps both his kids and their friends. Now, to return to the relative safety of their home while being reduced to a mere quarter-inch size, the minuscule humans must venture out into the dense and perilous landscapes of their now-immense backyard--a hostile environment where nearly everything spells trouble. Can the kids exit the green maze of grass in one piece?