It was winter, and Timothy, widowed mouse Mrs. Frisby’s youngest son, had taken ill with a high fever. It was so high that Timothy was not even interested in the breakfast of corn (always delicious, especially in the middle of winter when food was scarce), so she paid a visit to an old mouse, Mr. Ages, who was known to have cures for illnesses. Mrs. Frisby’s family lived in farmer Fitzgibbon’s garden for the winter, where there were more remnants of food available than in their winter home at the edge of the woods. The direct route to Mr. Ages, who lived in a clearing where he planted the herbs that he harvested for his cures, went through the territory of Dragon, Fitzgibbon’s orange tabby cat, so she took the longer route. In response to her description of Timothy’s symptoms, Mr. Ages said that he had pneumonia, and gave her three packets that would heal him, but he had to be careful not to go outside or even breath cold air for a month, or the pneumonia would come back and he would not be able to cure it.

It was getting towards night when she left, but on her way back she found a crow tangled in some tinsel. Despite it rapidly getting dark, she decided that she needed to help it, otherwise the cat would surely get it. It’s name was Jeremy, and after she convinced it not to keep trying to futilely fly away, she gnawed through tinsel and freed it. The cat had seen them, so the crow had her crawl on its back and he flew her back to her home.

The next day Mrs. Frisby realized that the weather had turned warm, and farmer Fitzgibbons would be plowing the garden soon, which meant they had to move to their summer house. This was partly because the plow would destroy their winter home, and partly because the humans were around the garden too much in the summer for it to be safe. However, while the days might be warm, the nights would be cold in the summer house, and Timothy would surely catch cold and, presumably, die. So she took Jeremy up on his offer of help, and he suggested talking to the owl at twilight; he sometimes answered questions. This did not sound at all safe, but having no other options she agreed.

Jeremey came about dusk, and she flew so high she could see the garden like a little square and the river like a blue-green snake. The owl required that she come in so he could see who he was talking to, which made Mrs. Frisby very nervous, but the owl kept his promise to not harm her—anyone who helped a bird from the cat was welcome. After she described the problem, the owl said that the house would surely be broken up by the plow, and since there was no use in all of them staying in the house and getting killed by the plow, they should take their chances on the move. Mrs. Frisby was almost crying when he took his leave of her, but realized that she had not told him her name. When she did, and she answered that yes, she was Jonathan Frisby’s widow, his attitude changed dramatically. In that case, he said, she should go to the rats, specifically Justin and Nicodemus, and suggest that they move the house to the lee of the stone.

This advice completely mystified her. All the animals knew that the rats had an entrance under the big rosebush, but they very much kept to themselves, and she did not see how her late husband would have had any relationship to them. Upon inspection, the rosebush looked impenetrable, until she noticed a smooth branch, which turned and revealed a tunnel through the bush, leading to a clearing in front of the hole, where light filtered down from a high ceiling onto mound in front on elegant entrance. The big rat there was named Brutus, and he told her to go away. So she left, but lingered at the entrance hoping that Justin would be there later. She was surprised to see Mr. Ages come limping in (he was likewise surprised to see her). He introduced her, and Brutus paid more attention to what she said this time, and admitted her.

The rat’s hole was even more impressive inside. There were small lights along the ceiling, and they traveled down in the freight elevator (which gave Mrs. Frisby a fright as it started sinking), since Mr. Ages could not manage the spiral staircase. Down below was even more impressive: more lights behind colored glass, lined ceilings, and carpet on the floor. She could even feel air blowing somehow this far underground. Clearly, as the owl had said, the rats were “not like the rest of us”. She was well-received by Nicodemus, but the rats were having a meeting about some Plan, so he had to wait in the library. Jonathan had taught her to read, which she could do very slowly, but the rats seemed to but much more proficient at it.

After the meeting, Nicodemus took her to his study and after swearing her to secrecy, explained the rats’ history. Twenty of them had been captured by people and used as what an older reader will recognize as laboratory rats. There were sixty rats total, in A, B, and C (control) groups. The A and B groups were given intelligence injections every week, with their performance analyzed with mazes and using images/letters. The A group, composed of the rats Mrs. Frisby was with, progressed very quickly, and the scientists moved on to steroid injections. Soon the rats had learned to read, and when they had read the instructions outside their cages, told them how to open their cages. They explored the air ducts night after night, locking themselves back in their cages so that the scientists would not realize their true abilities. The night they left, the mice in the same room asked to be let out; they had been given the same injections, but were too small to be able to open their cages. So the rats opened their cages and said they could escape with them, but after that they would go their separate ways. In the air ducts, a great wind would periodically blow, and the first time it happened it blew all the mice away, except for two that happened to be blown into the rats: Mr. Ages and Jonathan Frisby. The two mice were small enough to gnaw through the wire mesh on the vent to the outside and crawl under it, where they were able to open it from the outside. In gratitude the rats invited the two mice to join them.

The rats knew that any rats appearing unusually intelligent would be likely to get back to the scientists and they would be recaptured, so they kept to the edges of roads. Eventually they found a mansion whose owner was on his honeymoon for a number of months, and once they had figured out how to open the food cans, and tidied up after themselves so that the housekeeper would not be suspicious, they were able to have the house to themselves. They spent most of their time reading in the library, learning about the world.

After that, they sought an unpopulated place, ending up near a national wilderness. At the edge they happened upon a toy maker who had just died. His truck was filled with tools and motors that were the perfect size for rats, and they were able to take many of these before the truck was found and taken away. They settled at the nearby Fitzgibbons’ farm, where they had built a comfortable, civilized life, the first rat civilization and the first civilization apart from humans. However, a malaise had settled into them. Nicodemus, one of the leaders, came to the conclusion that the malaise was become they did not really have their own civilization—they were living on the edge of someone else’s civilization (the humans'). Their civilization was founded on theft; they did not have to work to maintain their civilization.

So Nicodemus and some of the others had come up with the Plan: they had located a valley in the middle of the preserve, not too far away, to which Men never came. There was a flat area where they could grow crops, so they watch Mr. Fitzgibbons and read up farming. And they stole enough seed of a variety of grains for two years crops, plus some extra food just in case the first crop failed. They had already moved most of it, and soon they would take all the lighting and wires and destroy them and all the machinery, so that they would not have the temptation to return to the easy life of stolen civilization. Some of the women were not entirely looking forward to it, but everyone was on board with the Plan except for seven of the rats, including Nicodemus’ fellow leader and childhood friend, Jenner. He saw no problem with stealing—rats had done it from time immemorial, and he was unwilling to give up the comforts of civilization. So the seven of them left and went on their own.

The rats were willing to help Mrs. Frisby, and they saw the wisdom in the owl’s plan. From his vantage point in the air, the furrows in the garden acted similarly to the wind, and if they moved the house behind the big rock instead of to the side, the furrows would go around the rock and leave a space untouched where the house would safe. The night promised to be warm, so Timothy would be fine. But first the cat needed to be drugged with sleeping powder. They had practice with this, although the hole was too small for the rats. Jonathan and Mr. Ages helped them put the powder on the cat’s food, and that was how Jonathan had died, and how Mr. Age’s foot was injured. Mrs. Frisby was frightened, but would do it for Timothy.

That evening, just before the Fitzgibbons ate supper, Justin took Mrs. Frisby to the hole under the floor. The cat’s bowl was two feet away, and after Mrs. Fitzgibbons filled it with the cat’s food and walked to the door to let the cat in, Mrs. Frisby needed to dash out out, dump the packet onto the food, and dash back. However, the cat’s bowl had been moved farther away, and the Fitzgibbon’s son captured Mrs. Frisby and put her in a cage. Mrs. Frisby was afraid that her children would be terrified when she did not return, but the good part was that she overheard Mr. Fitzgibbons talk about a group of six rats at a nearby hardware store that had been electrocuted while they had been seemingly stealing an electric motor (which turned out to be plugged in). There was a Doctor somebody that Mr. Fitzgibbons had talked to, and he had suggested that there were a bunch of rats by his barn that might be worth looking at. The doctor volunteered to come “the day after tomorrow” and fumigate the hole with cyanide gas.

Justin was waiting for Mrs. Frisby, so he had heard what happened to her. That night he came in and let her out of the cage (making sure to break one of the cheap fastenings of the door, so it looked like an equipment failure rather than an unexplained open cage). The cat was drowsy, as expected, and after Mrs. Frisby calmed down her shrew neighbor who was vociferously protesting to the rats that they could not take her neighbor’s house, the rats quickly and efficiently moved the house with pulleys and rollers. An added bonus was that if Mrs. Frisby and her family hid the opening, they could probably re-use the same house every winter instead of needing to find a new one.

Mrs. Frisby explained to Justin what she had heard, and the next day she was requested at the rats’ place to tell what she had heard. The rats accelerated their plans and put everything in a big heap underground, along with some fresh garbage, so that it looked like a normal rat hole. The men did come the next day, as Mr. Fitzgibbons had said. The rats had a dummy exit, and had made another exit behind the blackberry bush. When the men came, they all left out the back exit, weaving too and fro to make it seem like there were a lot of them. The men had been fooled by the fake exit, and saw the other rats too late to catch them. They also did not notice a rat that stumbled out of the fake exit and fell on the grass. After the men left, Mr. Ages gave the rat some medicine and he woke up and slowly recovered. It was Brutus, and he had been in the wrong place, and the cyanide had made it hard to think. A rat helped him out, and then had gone back in for the rat that Brutus had stumbled over in his escape. Mrs. Frisby suspected it was Justin, since it was a noble thing to do to go back, and Justin was a noble rat.

Timothy recovered well, and they moved to their summer house, which was nice for the children because there were several other mouse families by the edge of the forest and the children ran off to play together.

I read Mrs. Frisby and the Rats of NIMH when I was a kid, and I remembered it being both very good and also haunting. It did not disappoint on second reading and with some three decades or so of worldly experience. It does a good job of beginning as a normal animal story, kind of a Borrowers meets Watership Down, immersing you in life at three inches high. So it comes as a surprise (on first reading, anyway) when Mrs. Frisby sees the inside of the rats’ home and discovers a civilization advanced beyond her ken. Who are these guys, and what are they doing that they need to be so secretive?

As a kid the idea of living on the edge of someone else’s civilization went completely over my head, as did the malaise from a too-comfortable where all your needs are provided for by someone else. Not only does this touch on the ennui that Sherlock Holmes and wealthy people of his era comment on (e.g. the people in The Great Gatsby except for Gatsby, who have no real purpose for life, or the kid in Catcher in the Rye), but it could be a commentary on our own civilization. We are living at the edges of someone else’s civilization—our ancestors’ civilization—and if we coast comfortably instead of continuing the work of building civilization, we may end up in a similar malaise. Apparently the book was inspired by John Calhoun’s rat experiements at the National Institute of Mental Health (as I kid I thought “Nimh” was an odd name; I’d never heard of the government research agency). He built a rat utopia, where they had everything provided for, and he found that what inevitably happened was that the population would expand to the point of overpopulation, and then just die off. The final generation was, as he termed it, “the Beautiful Ones”: they spent all their time grooming themselves, and did seem to have any idea how to care for their young, and did not have much interest in breeding anyway.

There’s also an interesting line by the owl, where he empathized with Mrs. Frisby’s plight, because sitting in his tree, he had noticed that it was making new sounds: it was close to breaking. But he was an old owl, and both did not want to deal with the change of finding a new home after so many years, nor the hassle and risk of fighting for a new place. So he observed that when the tree fell, if he was still alive, he would fall with it. It is unclear whether this is just a general observation of a certain perspective of elderly people, or whether it serves to highlight how the rats are different. It also went completely over my head as a kid; I am not even sure if I could have understood it. But it is a somber observation or warning, and definitely as I grow older I can sympathize with why one might choose that path.

The book is still just as haunting as when I was kid. Mrs. Frisby discovers a new, magical world (and in the process goes through a sort of hero’s journey), but that world disappears. Unlike the more normal hero’s journey, it is the rats who suffer loss (two of the rats do not come out) and are the ones who are most changed. Indeed, they abandon their magic for a less magical but more virtuous civilization that they build themselves, without stealing from others. Do they succeed? We do not know, although we assume they probably do. Still, even if they do, something amazing has been lost. Even if it is just the stolen and repurposed civilization of others, it is still something amazing that now no longer exists, nor is it something that the remaining animals could ever hope to recreate. Unless, perhaps, Mrs. Frisby’s children inherited their father’s augmented intelligence.