A year has passed since Basil's battle with Ratigan atop Big Ben, and the Flavershams have moved to the American West to put that horror behind them. However, once arriving in Green River, Olivia's father is kidnapped once again. Can Olivia hone her detective skills to save him? Luckily, she'll get a little help from one Fievel Mousekewitz! (Sequel to Basil's American Tail).

In 1886, Basil of Baker Street, fresh off of busting Ratigan's latest heist at the British Museum, travels to New York City in search of stolen artifacts which he discovered had been sold on the black market. Upon his arrival he's assigned someone from the NYPD to be his body guard, who, as Basil deduces, is actually a woman in disguise, a reporter named Nellie Brie.

Tom and Jerry are lost in the West and stumble across Green Rivers. There, they meet Fievel and his friends, but also the return of Warren T. Cat and Cat R. Waul, who are scheming to turn the mice of Green Rivers into food for Warren's popular mouse restaurants. Fievel, his friends, and his new companion Jerry must work together to avoid becoming food.