An American Tail: The Treasure of Manhattan Island

In an abandoned subway, Fievel and Tony stumble upon the remains of a dead mouse clutching a treasure map. They realize the map points to something buried beneath Manhattan. The find sets them on a new adventure.

They consult Dr. Dithering, who deciphers the map and confirms it leads to an underground Lenape treasure beneath Manhattan. He organizes an expedition and gathers Fievel, Tony, Tiger, and Scuttlebutt. The team prepares for the perilous journey.

The group navigates traps on their way to the buried settlement. They discover that the 'treasure' is not gold but a village of Lenape mice protected underground. The revelation reframes what they are seeking.

The Lenape welcome the surface visitors but explain they retreated underground upon witnessing how humans mistreated them. Chief Wulisso recommends cautious contact and mutual respect. Cholena is chosen to go to the surface to test whether humans have changed.

Back on the surface, Fievel's father and Tony work at a cheese factory. Workers are overworked and underpaid, growing resentful. The factory's intimidation by the corrupt NYPD chief McBrusque keeps them in line.

Upon return, Scuttlebutt reports the Lenape village to the factory owners, who see a chance to manipulate the workers by stoking anti-Native sentiment. They plot to capture Cholena and anyone aiding her. The plan broadens the conflict between the surface and the underground.

Fievel and Tony rescue Cholena from the police, while Dr. Dithering is captured by the mob and taken toward the butcher shop for trial. Papa and Tiger organize a counter-effort to free him. The rescue marks a turning point in the workers' and villagers' united front.

At the butcher shop, Dithering is sentenced to death but Tiger saves him. Papa addresses the crowd, revealing how factory owners use xenophobia to divide workers. The crowd turns against the factory owners as they flee.

Returning Cholena to her home, Fievel informs the chief of the danger. McBrusque and police assault the village, but the chief and the Lenape resist. The chief provides a gunpowder bomb to seal the tunnel.

McBrusque and Scuttlebutt ambush the group in the tunnel. Fievel and Tony fight them off as the bomb is set. The explosion floods the tunnel, sending McBrusque and Scuttlebutt to their deaths. Fievel appears to be carried away by the current.

Tony and Tanya reach higher ground while Fievel is swept away by the water. After the flood recedes, Tanya and Tony search the mud for Fievel and finally find him. They share a muddy group hug, grateful that everyone survived.

Papa forms a workers' union, pressuring the factory owners to negotiate to avoid a strike. Tiger becomes the new police chief and ensures order without xenophobia. The workers' solidarity pushes the city toward fairer treatment.

Using a foldable telescope from Dr. Dithering, Fievel spots Cholena and her father slipping through a hidden door at the base of the Statue of Liberty. He wishes for the Lenape's safety and a better future on the surface. The ending implies hope that both communities can coexist.