The Secret of NIMH

Mrs. Brisby cannot move because her youngest son, Timmy, is seriously ill with pneumonia. Moving a sick child, especially one with a serious respiratory illness, could worsen his condition or even be fatal. This is why they remain in their endangered cinder block home despite the plowing threat, a difficult choice that drives much of the film's tension.

Early scenes establish Timmy's frailty and the family's concern for his health, making the impossible choice to stay appear logical.

NIMH stands for the National Institute of Mental Health, a fictional government research facility where the rats were subjects of intelligence-enhancing experiments. The rats escaped from the laboratory after gaining superhuman intelligence, which is why they can speak, plan, and build an advanced society using stolen electricity. Their origin explains both their intelligence and their deep distrust of humans.

The Great Owl mentions that the rats have a mysterious past, hinting at their laboratory origins before the full explanation.

Jenner is power-hungry and resents Nicodemus's leadership. He believes the rats should not rely on stolen electricity and wants to establish their own dominion rather than living in hiding. Jenner sees Nicodemus's plan to relocate to Thorn Valley as weakness and betrayal, so he murders Nicodemus to seize control and sabotage the evacuation, believing he can lead the rats more effectively through force.

Jenner's hostile demeanor and challenging questions to Nicodemus during the planning stages foreshadow his intentions.

The amulet is a mystical artifact belonging to the Rats of NIMH, given to Mrs. Brisby by Nicodemus as thanks for her help and as a token of the rats' debt to her late husband, Jonathan. The amulet represents courage and contains magical properties that allow its wearer to perform extraordinary feats. When Mrs. Brisby uses it in desperation, the amulet grants her the strength to lift her entire cinder block home, a feat that would be impossible for an ordinary mouse.

Nicodemus specifically entrusts the amulet to Mrs. Brisby, suggesting it holds significance beyond ordinary token exchanges.

Mrs. Brisby lifts the cinder block home using the magical amulet given to her by Nicodemus. While the amulet's magic is never fully explained, it channels the wearer's determination and maternal courage into physical strength. In the film's climax, with her children in imminent danger from the plow, Mrs. Brisby channels her desperate love and the amulet's power to accomplish the seemingly impossible, raising the entire house long enough to escape with her family.

The amulet is presented as a significant magical object, and the buildup to this moment emphasizes that Mrs. Brisby needs something beyond ordinary courage.

The Great Owl knows Jonathan Brisby because he was a hero among the animals of the farm. Jonathan previously helped the Rats of NIMH escape from NIMH, and the Owl explains that he witnessed Jonathan's brave actions. This prior connection is why the Owl trusts Mrs. Brisby enough to guide her to the rats, the debt the rats owe to Jonathan extends to his widow and their children.

The Great Owl's initial interest in Mrs. Brisby suggests there is more to her visit than simple curiosity.

The Rats of NIMH owe their freedom to Jonathan Brisby, Mrs. Brisby's late husband. Jonathan helped the rats escape from the NIMH laboratory during their escape attempt. This act of bravery created a lasting bond between Jonathan and the rat colony, which is why Nicodemus pledges to help Mrs. Brisby, repaying the debt they owe to her husband for giving them their freedom and intelligence.

Nicodemus mentions Jonathan by name early in their meeting, indicating a pre-existing connection.

Mrs. Brisby volunteers to sedate Dragon, the farmer's vicious cat, as part of the rats' plan to secure an escape route to Thorn Valley. She offers herself because she wants to prove her commitment to the rat colony and earn their continued help in saving her family. However, her attempt goes wrong when she becomes trapped in the cat's lair, where she overhears Jenner's conspiracy to kill Nicodemus and take control.

Mrs. Brisby's willingness to face a dangerous predator demonstrates her growing courage throughout the film.

After Jenner kills Nicodemus and the surviving rats attempt to evacuate, they depart the rosebush to relocate to Thorn Valley as planned. The film implies they successfully escape, though the exact fate of the rat colony is not fully shown. However, the ending reveals that NIMH has begun investigating the abandoned rosebush, suggesting the rats' departure may not fully protect them from the laboratory's reach.

Nicodemus's death and the subsequent chaos directly trigger the rats' hurried evacuation from their longtime home.

Nicodemus trusts Mrs. Brisby because she is the widow of Jonathan Brisby, the rat who helped the NIMH rats escape from the laboratory. This personal connection to their savior creates an unpayable debt. Additionally, Mrs. Brisby proves her courage and sincerity by seeking out the dangerous Great Owl and traveling to the rosebush despite her fears, demonstrating she is worthy of their assistance.

Nicodemus's immediate pledge to help upon learning her identity shows the depth of the rats' gratitude toward Jonathan.

Jeremy is a clumsy but genuinely kind-hearted crow who helps Mrs. Brisby simply because she asks for assistance. Though crows and mice are natural enemies in the wild, Jeremy shows compassion for her desperate situation and acts as her guide to the Great Owl. His character represents unexpected kindness and friendship across species lines, and his later romantic happiness at the end reinforces his role as a helper who finds his own reward.

Jeremy's initial awkwardness contrasts with his eventual courage and loyalty throughout their journey.

An unexpected warm spell arrives in winter, causing Farmer Fitzgibbons to begin plowing his fields much earlier than planned. This sudden change threatens Mrs. Brisby's home beneath the cinder block, as the farmer's plow moves toward her family巢 before they can relocate. The warm weather is a natural occurrence that creates the film's central time pressure, the family must act quickly or face destruction.

The opening scenes establish the early warmth as a problem that sets the entire plot in motion.

Yes, Timmy recovers from pneumonia by the end of the film. After the harrowing night where Mrs. Brisby saves the family using the amulet, the new day brings the hopeful news that Timmy is getting better. His recovery marks a turning point for the Brisby family, symbolizing that their struggles have resulted in a safe future together.

Timmy's illness is established early as the central reason the family cannot simply move away.