When Zack and Spencer get the late-night munchies at a sleepover, they curb their hunger with some freeze-dried food that Zack got at the Air & Space Museum. After devouring freeze-dried ice cream and pizza, they come across an extra package of freeze-dried something. When opened and wet, the shriveled mass starts growing, and growing and growing! How will the boys stop an out-of-control blob from eating everything in sight before it's too late?