When all the potatoes in Danville go missing, Phineas and Ferb decide to clone some using Buford's last potato chip so that Isabella's Nana can make latkes for the Latke Festival at the Danville Senior Lodge. Unfortunately, Buford's DNA also merges with the potatoes, creating mischievous Potato Gremlins all over town. Meanwhile, Dr. Doofenshmirtz's plans on using his latest "-inator," a potato-powered "Historical Army Retrieve-inator," to summon the Spartan army and command them to take over the Tri-State Area.