Roddy is a decidedly upper-crust "society mouse" who lives the life of a pampered pet in a posh Kensington flat. When a sewer rat named Sid comes out of the sink, he desides he had hit the jackpot. Roddy schemes to rid himself of Sid by luring him into the "whirlpool." Sid may be an ignorant slob, but he's no fool, but it is Roddy who winds up being flushed away into the bustling sewer world of Ratropolis. There Roddy meets Rita, an enterprising scavenger...

Set at the dawn of time, when prehistoric creatures and woolly mammoths roamed the earth, this tells the story of Dug, along with sidekick Hognob as they unite his tribe against a mighty enemy Lord Nooth and his Bronze Age City to save their home.