Wayne Szalinski is at it again. But instead of shrinking things, he tries to make a machine that can make things grow. As in the first one, his machine isn't quite accurate. But when he brings Nick & his toddler son Adam to see his invention, the machine unexpectedly starts working. And when Adam comes right up to the machine, he gets zapped along with his stuffed bunny.

Arthur Bishop is a veteran hit man who, owing to his penchant for making his targets' deaths seem like accidents, thinks himself an artist. It's made him very rich, but as he hits middle age, he's so depressed and lonely that he takes on one of his victim's sons, Steve McKenna, as his apprentice. Arthur puts him through a rigorous training period and brings him on several hits. As Steven improves, Arthur worries that he'll discover who killed his father.

Police in Boston search for a mad bomber trying to extort money from the city.

A crew of scientists arrives on a far, cold planet to examine archaic artifacts of unknown origin. They discover that their German enemies already have a ship there. When they seek their help after a failed landing, they only find the Germans’ bodies, obviously slaughtered by one of the archaic creatures, awoken to new life. Now the alien is after them.