With Stu and Didi away at an Invention Convention, Tommy and Dil want to host a viewing party for a "real" alien autopsy video. But when both Grandpa Lou and Grandpa Boris show up to babysit the kids, can theÿgang find a way to watch the "inappropriate" tape before Dil has to give it back?

When Tommy forgoes going to the traditional opening day ball game outing with his Grandpa, Lou takes Dil instead. This makes Tommy jealous as he and Dil compete to be Grandpa's favorite grandson during a fishing trip.