Plant pals Nate and Patrice try out a new idea: thwarting zombie attacks by putting defending "Guard-ens" plants inside homes as well as in yards! But as soon as zombie leader Dr. Zomboss finds out, he quickly becomes obsessed with circumventing this plan with an epically evil one of his own: building cages disguised as homes to trap all the tasty brains (and the people they reside within) before the Guard-ens can get there!