Rex and his friends are in the process of fixing up the patio behind the house. But a group of ants who live in the backyard are not about to go without a fight.

Rex finds his birthday present that Bad Bob has been working on: a working rocket pack like his childhood hero's, "Rocket Raymond." Rex eagerly tries it out, and gets sent on quite an adventure into space.

Rex goes to Dr Dog, and returns home missing an ear. The gang returns to Dr Dog's to investigate, and find that the physician has now begun to shift his focus to genetic engineering.