Rick Moranis stars as lovable dad and ambitious college professor Wayne Szalinski, who has recently become something of a laughing stock to his peers when he dares to introduce a potential way to drastically reduce the size of everyday objects.  His own experiments have proved futile, but a fluke accident causes the reduction machine to finally work -- too bad the Szalinski children are the ones in the ray's path, along with the rambunctious neighbor kids, the Thompsons.  Wayne accidentally tosses the kids out with the trash, causing the miniscule kids to have to venture through the entire yard and hope they can grab the attention of their parents, and, hopefully, the professor can figure out a way to grow them back to normal size again.  Making it there proves more difficult than it would seem, with treacherous bugs and other pollutants blocking the way at nearly every turn.