Racso and the Rats of NIMH

Racso and the Rats of NIMH is a sequel to Robert C. O'Brien's Mrs. Frisby and the Rats of NIMH written by Jane Leslie Conly, who also wrote the sequel novel R-T, Margaret, and the Rats of NIMH.

Summary
Three years after the Rats of NIMH have relocat to Thorn Valley, Timothy Frisby prepares to leave to attend the rats' school. Jeremy, who has previously served as Timothy's transportation, is unable to fly him there due to his mother being injured. As such, Timothy-with the permission of his mother Mrs. Frisby-sets out for the valley on foot. On his way there, he finds signs of another creature's passage and eventually encounters a young rat named Racso. A city rat, Racso reveals that he is searching for the Rats of NIMH, and Timothy soon determines that he is the son of the presumed deceased Jenner.

The two begin making their way to Thorn Valley together, only to be attacked by the Owl, who badly injures Timothy before releasing him after Timothy shouts out his name. Justin, who survived the destruction of the rats' previous colony, writes to Mrs. Frisby informing her of Timothy's failure to arrive. She is then brought to the Owl, who confesses that he attacked Timothy and believes him to have been killed. However, Racso tends Timothy and, with some of the mouse's knowledge, is able to help him begin recuperating.

Racso is able to pull Timothy in a sling nearly to Thorn Valley, where they are met by a party of rats led by Justin. After arriving at the valley, Racso meets with Nicodemus, and after attempting to lie about his origins admits that Jenner is his father. He is allowed to remain at the valley and attend school, but asks Nicodemus not to reveal the truth to anyone. Meanwhile, the rats discover that the nearby Trout River, which has been rising unusually high, is in danger of flooding the entire valley.

As the rats endeavor to discover what is causing the flooding, Racso attempts to adjust to life in Thorn Valley. He makes a friend in the young rat Christopher, but also manages to annoy other young rats and older rats with his behavior. The rats discover that a dam is being built in Thorn Valley, and Mrs. Frisby soon arrives with news that it will destroy not only the wildlife preserve but also the surviving farmlands and towns. With the lives and livelihoods of humans and animals alike threatened, the rats meet to determine what course they should take.

Having had experience with a computer, Racso suggests using the one that will be running the dam against the project. His suggestion is agreed upon, and the rats set out to learn as much as they can about computers. Several rats, along with Racso and Timothy, are also inducted into a training group from which the mission team will be selected. Racso begins improving his relationship with the other young rats, but becomes worried when they nearly stumble upon his father's true identity.

Racso counsels with Nicodemus, who advises him to admit to his lies and tell his friends the truth when he feels ready. Sadly, during a surveillance mission his friend Christopher is badly injured, falling out of a tree while observing two humans. Christopher becomes gravely ill, prompting Timothy to suggest sending word to Mr. Ages for medicine. Meanwhile Racso, working together with Isabella, makes peppermint candy and feeds some to Christopher, who begins improving.

Racso is chosen for the mission team, which sets out for the dam and begins gathering information in preparation for their mission. Unfortunately, in the process of using a copy machine to copy instructions for the dam computer, one of the rats is discovered and captured by security guards. Racso is able to save the rat, Beatrice, from being killed, and though he is captured as well the other rats later free them. Finally, the rats set out to enter their own program into the dam computer, only to run out of time.

However, just after the failed programming attempt, the main power supply to the dam is cut, leaving the rats another night to complete their task. Upon investigating, they learn that Jenner had followed Racso to Thorn Valley and, learning of the dam, sacrificed his own life to sabotage the development. His actions allow the rats to complete their sabotage mission, and they hold a memorial service for him. While Racso is now fully one of the colony, Justin worries that stories of rat activity at the dam may spread.

Birds

 * Jeremy
 * The Owl

Humans

 * Representative Jones
 * Lindsey Scottweferfef
 * Jack
 * Hank
 * Ray
 * Mr. Fitzgibbons
 * Mrs. Fitzgibbons