Mr. Peabody (Ty Burrell), the most accomplished canine in the world, and his boy, Sherman (Max Charles), use a time machine called the Wabac to embark on outrageous adventures. However, when Sherman takes the Wabac without permission to impress his friend Penny (Ariel Winter), he accidentally rips a hole in the universe and causes havoc with world history. It's up to Mr. Peabody to mount a rescue and prevent the past, present and future from being permanently altered.