The novel is shaped like a child book. It tells us about the adventures of some little fluffy rabbits, but if we read attentively, we’ll see the lots of allusions to mythology (especially “Iliad”, “Odyssey” and “Aeneid”), the modern politics and some historical events. But still, you may choose to look at the rabbits and read it like a light adventure story that can be a great plot for the Disney movie.
The story starts from the description of the big and peaceful rabbit warren named Sandleford. There is plenty of food and rabbits prosper and reproduce. But once a little and a bit odd rabbit named Fiver starts to worry. Fiver has a strange ability to sense when something is going to happen and whether it will be a good or bad event. This time he foresees something very bad very soon. His feeling is so awful that he is going to flee to nowhere from Sandleford and urges everyone to go with him.
At first no one believes Fiver except his big brother Hazel. Hazel tries his best to arrange a meeting of Fiver and the leader of the warren - the big and old rabbit named Threarah. Thearah listens to the little rabbit, but dismisses his worries outright. He won’t risk the whole warren because of some superstitions of a silly child. But Hazel keeps trying. He tells everyone in the warren about Fiver’s feeling and some of the younger rabbits indeed decide to flee before they are endangered. They are two friends of Hazel named Dandelion and Blackberry and one smaller rabbit, who is Fiver’s friend named Pipkin. When the friends are ready to go, suddenly, another member joins their party. His name is Bigwig, he is a grown rabbit and one of the members of the warren’s “government”. He isn’t as old as Thearah, but he is the biggest and strongest rabbit in Sandleford. He decides that Fiver wasn’t wrong before, so he deserves trust now too. With Bigwig’s authority it is easier to convince the others to come with them. Another ones named Silver, Buckthorn, Hawkbit, Speedwell, and Acorn join the company. Hazel is the formal leader, though he listens to Fiver’s prophecies and Bigwig’s practical advice choosing the direction. The rabbits start their journey.
Their way isn’t easy - they never went so far from their warren - but the rabbits have their unique talents that help them survive. For example Dandelion is a skilled storyteller who keeps the morals of the party high, telling them the story of the mythical rabbit hero El-ahrairah. Blackberry is a natural inventor who makes a raft to cross the river (not a big deal for humans, but the characters are rabbits, don’t forget it). Each of the rabbits plays an important part and contributes to the whole party.
Finally the rabbits, alive and intact, arrive to a beautiful meadow. There is plenty of food just lying everywhere and the warren of rabbits, almost as big as their own, led by the rabbit named Cowslip. Cowslip is a very lenient (or shall we say ignorant?) leader, because the warren doesn’t seem to need leadership: they don’t need to search for food for too long and don’t need to protect themselves from the predators. The rabbits are glad to finally find a place to call home, but Fiver still senses something odd in the new warren. Hazel listens to his brother, telling the rest of the rabbits just to rest here, but not to join the warren as full-fledged members. But the rabbits are too tired and don’t want to move anywhere. On the meadow the life is easy and food is free, so why should they search for something else? Even Bigwig agrees that it is the perfect place to live. Now Hazel can’t find the words to persuade them, so he and Fiver have to tolerate the decision of the majority.
Once, after a quarrel with Fiver Bigwig angrily goes away and gets captured in a snare. Now Fiver understands what was so wrong and what was his feeling about. The rabbit warren is fed by the neighboring farmer. He wants the rabbits become fatter and procreate often, so he can regularly catch them for food. Bigwig, Hazel and others, seeing that their prophet is right again, try to convince the inhabitants of the new warren to go with them - but only one rabbit named Strawberry decides to join them. The other either don’t believe or don’t seem to care at all.
The rabbits continue their journey until they reach Watership Down. Despite the name it is a perfect field and - what is most important - it seems uninhabited. Now even Fiver doesn’t object: it is indeed a great place for the new warren. The rabbits start digging. When they are about to finish, the two familiar rabbits - Holly and Bluebell, the former dwellers of Sandleford - reach them. Both are exhausted and terrified. They tell that right after the Fiver and others left Sandleford the humans came with a terrible poison and killed everyone in the warren as pests. Holly and Bluebell are the only two survivors left.
Though shocked by the news, rabbits accept the newcomers and finish the building of the warren. But suddenly they realize that they are all males. Without females their new warren will die out very soon, so they need to find partners for mating and do this quickly. Luckily they found a wounded seagull named Kehaar and nurse it back to health. Kehaar is so grateful that it agrees to fly around and look for the other wardens to find them some single female rabbits. Soon Kehaar returns and reports that there are two places that are relatively near: human farms where rabbits are bred and the warren in two days from their own named Efrafa.
Hazel decides to examine both places. He himself chooses the farm as a more dangerous place, taking with him Fiver and his closest friends. Hazel also sends some of the other rabbits to Efrafa to have a look. At the farm Hazel sees the miserable lives of caged rabbits and decides to free everyone he can, disregarding their gender. He opens three cages, but when he frees the fourth rabbit, the farmer comes and shoots the wild rabbit. Hazel is badly injured and left behind. On halfway Fiver returns to rescue the body of his brother - despite everyone else thinks it isn’t worth their lives - and when he drags Hazel out of the farm he discovers that he is alive. The rabbits return to the warren, but, unfortunately, all the rescued ones are also males. Hazel slowly recovers, but he is left permanently disabled and the other rabbits have to care for him.
The second party returns with the news about Efrafa. They tell that this warren doesn’t look like any other. It is a highly militaristic totalitarian “state”, hostile to outsiders. Every rabbit inside is indoctrinated by propaganda of the warren ruler named General Woundwort. General Woundwort definitely isn’t going to give away his females. But Hazel understands that this is their only option to save their warren from extinction. He understands that they can’t attack Efrafa, so he comes up with a cunning plan of infiltration. Bigwig volunteers to go, because he is the most likely to pass for a dumb brute Woundwort values.
At first the plan goes smooth. Bigwig is accepted in Efrafa and even is soon given an officer position and the permission to freely walk the warden. Bigwig finds a group of females, who are extremely unhappy with their lives but aren’t allowed to go anywhere else. The smartest of them named Hyzenthlay helps Bigwig to plan the escape from Efrafa. But the plan appears to be not as perfect as they thought: the rabbits are spotted and chased. The guardians of Efrafa would have probably kill them if not Kehaar attacking them from above and Hazel (who, despite his disability, comes to aid along with Kehaar). Bigwig and Hyzenthlay manage to escape along the reinforcements with the newly built raft (Blackberry is indeed local Leonardo Da Vinci - his second raft resembles a real boat). It seems that now the warren is safe.
It is safe for some time - until their reckon mouse (who also was saved by the rabbits before and adopted to the warren) reports that General Woundwort didn’t take the stealing of females easily. While they were fleeing, one of the officers who led the chase named Captain Campion tracked them down and now Efrafians know where their warren is. All this time General Woundwort gathered a huge army and this army is now marching to their warren to raze it and kill everyone inside.
The warren is doomed. But still Hazel orders everyone to prepare for a siege. The rabbits dig even deeper tunnels, turning their home into a maze, and prepare to defend it, even if the try will take their lives. Watership Down is their Promised Land and they won’t let anyone take it from them. Hazel manages to raise the morals of the defending forces but he understands that the battle will be truly hopeless. Suddenly, he has an equally crazy and brilliant idea: Hazel remembers that the farmer who injured him also had a dog. If only he sets the dog free, it will attack the rabbit army of General Woundwort that shall cross the farm field. Hazel asks Dandelion to help him and the two rabbits go to their suicide mission.
Meanwhile, the warren is under a heavy siege. Bigwig confronts General Woundwort, who is huge and incredibly strong for a rabbit. The two fight, Bigwig is seriously wounded but he finally manages to defeat the enemy. Too bad that the rest of the army is still intact and is ready to avenge their General…
Hazel sets the dog free. He and Dandelion manage to survive through it and the dog, smelling rabbits’ scent, immediately runs towards the army of Woundwort. Hazel and Dandelion try to escape, but the warren leader is still crippled. He can’t run as fast as Dandelion and is caught by a cat. The cat is almost ready to eat him, but a little girl - the farmer’s daughter, who went to have a look at what their dog is barking at, rescued him. The kind girl berated the cat and set Hazel free. The brave rabbit is lucky: he is still able to go on his own feet.
When Hazel and Dandelion reach their warren, they see that everything worked just as planned. The enemy army fled with heavy losses, but the dwellers of his warren were safe in their deep tunnels. Soon, Captain Campion, who became a new leader of Efrafa, replacing General Woundwort, comes to them to make a truce. They decide to stop the war and build a third warren together on the neutral territory, so the rabbits from both warrens will be able to live there if they want to. So no one will need to steal females no more and no one will rebel against the existing government, because they will always have an option.
Hazel lives an exceptionally long life for a crippled rabbit - he was honored and cared for to his very last day. When he dies, content and seeing his warren growing and prospering, the rabbit storytellers said that he went to join El-Ahrairah in the pantheon of heroes. Lots of rabbit generations now will listen to the stories, myths and fairy-tales about Hazel’s life.