In October 1959 of the fictional town of Oakton City, a squirrel named Surly and his mute rat partner Buddy reside in Liberty Park where their thieving reputation has made them outcasts. A group of urban animals led by Raccoon and his cardinal assistant are running low on food for winter.

Compassionate squirrel, Andie, and glory hogging squirrel, Grayson, compete with Surly and Buddy to scavenge from a nut cart run by Lucky and Fingers who are casing a bank. The squirrels' efforts inadvertently end with the cart's propane tank exploding in the park after its cord was bitten by Fingers' pug Precious. The runaway cart ends up destroying the animals' food supply, resulting in Surly's banishment from the park.