
(?) as Arthur 'R.T.' Livingstone - the human boy with autism and best friend of Christopher. (?) as Christopher - Best friend of Artie. Thorn Valley celebrated for Margaret and Artie. Livingstone are happily and found their children and hugged each other. Margaret and the animals must rescue RT and his gang. Margaret told them they must get out of there. Margaret sang and the animals heard, so they're coming and cheered. In the beginning, The Livingstone family are going camping.
but it's hard to evade questions forever. And when they do, they must protect the rats who have helped them. Margaret and Artie have to get back home.
Taken into the rat's community, the children are safe for the time being. When a human girl named Margaret and her younger brother, Artie, get lost in the woods on a family camping trip, they are rescued by rats - the super intelligent rats of NIMH. This film takes place after the second film or television series.