Following the liberation (and destruction of Efrafa), the Efrafans move into Watership Down with Moss, the highest-ranking surviving officer, as their reluctant leader. Tensions are high as three of the other surviving officers try to bully Pipkin and end up getting into a fight with Bigwig. Meanwhile, Woundwort has survived and runs into two other rabbits in a swamp, letting them sink to their deaths in a mire after they refuse to swear loyalty to him. The Black Rabbit of Inlé shows this to Campion and tells him that his destiny is stop Woundwort, who "threatens the world of the living." Campion has a horrible vision of Blackberry in danger, and himself being threatened by a fierce green rabbit. Meanwhile, Moss and Heather decide to take the rest of the Efrafans to start a new warren elsewhere.

Vervain wanders about aimlessly, getting into all sorts of trouble. Bigwig, meanwhile, continues to push his Owsla. In the end Bigwig eventually accomplishes his goals and in doing so saves Vervain from getting into any more trouble.

The Junior Owsla and Kehaar help an orphaned Hawk survive, whilst at the same time trying to prove to Hazel they are responsible enough to go on solo patrol. What they don't know is that Hazel has been secretly watching them save the Hawk.

Undercover, Woundwort begins to gain the trust of the rabbits at Redstone Warren. He has to fight off his own allies in order to finally gain there trust. Meanwhile, Blackberry finds out about Campion.

Woundwort works his way to chieftainship of Redstone. Meanwhile, Kehaar decides to leave the warren for good with his new mate Gluck.

Woundwort discovers that a human construction crew plans to bulldoze Redstone. He and Vervain travel to the Warren of the Shining Wire where he tells Cowslip he will show him Redstone destroyed if Cowslip will give him his seer, Silverweed. Meanwhile, Hickory and Flax talk of revolt against "Weedstalk" while Marigold races to Watership Down to warn Hazel and the others of Woundwort's return. The wandering Campion stumbles across a new warren, Darkhaven, populated by savage rabbits who await the prophesized return of "the Dark One." He becomes their chief after he defeats their strongest warrior, Granite, winning the respect of a tough doe named Spartina.

Woundwort, Vervain, and Silverweed arrive at Darkhaven just in time to meet up with Campion. At the same time, Hannah learns magic so that she can help her friends.

Silverweed traps Fiver in a twisted dreamworld illusion, allowing him to invade Fiver's mind and see through his eyes to learn the location of Watership Down for his master, Woundwort. Fiver manages to fight off Silverweed's hold, but not before Silverweed deduces that Watership Down is "in the high hills, near a lone beech tree." Hazel realizes how dangerous Silverweed is so he and the others journey to Darkhaven with the intent of kidnapping him. Meanwhile, Campion and Blackberry have the same idea, whilst Granite becomes Woundwort's new second-in-command when he challenges Vervain to single combat. Vervain forfeits rather than face the stronger Granite.

Spartina is sent by Woundwort to befriend Hazel and the others and act as a spy for him. However Silverweed soon learns of her real objective. If Spartina does not return to Darkhaven by the next full moon, she has ordered Granite to kill Blackberry.

Spartina soon gets found out by the other Watership Down rabbits and she confesses everything, even admitting putting Blackberry in danger. After finding out about Spartina's betrayal, Woundwort uses her and Blackberry to make Campion confess where Watership Down is and to lead his army into battle there.

The Watership Down rabbits prepare for the last battle with Woundwort while Blackberry, Spartina and Campion plan their escape from Woundwort.

Since the apples of the orchard are red and delicious Hazel and Bigwig go down to have a munch but retreat back to the warren when they find out a badger lives there. Knowing that the orchard is off-limits, Pipkin and Fiver go down to have a bite of the apples anyway. The badger comes back, and Pipkin flees. Fiver soon finds out the badger is harmless, and has a name: Bark.

After a huge storm, multiple sheep are at Watership Down. For now, Hazel agrees to let them stay. After living with them for a while, he soon finds out they aren't friendly and they attract more enemies. Captain Broom explains what a sheepdog can do to get rid of the sheep. Hazel hatches a cunning plan to get the sheep out of the down.

Primrose feels a little homesick for Redstone. Hazel agrees to take her back despite Fiver's warning that Redstone is empty. On the down, Fiver has another vision that one of their past enemies will return. Meanwhile, Hazel and Primrose are shocked to find that Fiver was right about Redstone being empty. The only one left there is Captain Broom.

Hickory and Marigold decide it's time to leave Cowslip's warren and set off to find Hazel. Hazel agrees to help them escape, and Hawkbit and Dandelion give them lessons on how to live outside in freedom. Hickory and Marigold decide to start a new warren. Concerned, Primrose suggests that they move into Redstone. Trouble is ahead of them though, when Hickory gets trapped on a roundabout.

Unconvinced that Buttercup's warren is safe, Hazel and his friends decide to flee during night. However they soon find out that Buttercup's warren is harmless, and the men that live nearby are harmless as well. Buttercup lets them take as much food as they want and Kehaar leads them back home safely to Watership Down.

Wondering the burrow, Hawkbit discovers a strange chamber and believes he saw The Black Rabbit of Inlé. Concerned, Hawkbit goes to check it out again with Hazel and Fiver, but they encounter a cave-in. Bigwig believes Hazel, Fiver and Hawkbit have been kidnapped by Efrafa.

Bigwig and Hazel worry about Watership Down being wiped out and that they have no idea of Woundwort's plans. Deciding that they will try to get Campion on their side they find him out on patrol and ask him to join up with them. Things seem to be going well, until Pipkin is taken away by the river after attempting to swim.

It's snowing and the grass has turned white. The rabbits plan on having a big feast. But with no food Hazel, Bigwig, Hawkbit, Dandelion, Fiver and Kehaar set off to find some. They become lost, and encounter danger with a fox and ice. A rabbit named Buttercup comes along and allows the rabbits to say at her warren, right near a man.

Kehaar becomes homesick of the Big Water and decides he must go and visit it, with the rabbits tagging along too. Smelling the glorious smell of carrots and lettuce, the rabbits wander inside a big farm van to nibble at the food. Suddenly the van drives off, and the rabbits find themselves at a market where they make friends with a pig.

Hazel, having had new babies, decides to take a trip to the farm with Bigwig, Fiver, and Hawkbit in order to find food for the baby rabbits. Everything seems to be going well until they encounter a dog and a cat. Hannah gets herself into trouble too.

Hawkbit, Fiver, Pipkin and Dandelion raid the farm and to Hazel's surprise, they bring two other rabbits back to the down instead of food. Bluesky and Raincloud both say they are messengers from Prince Rainbow. Hazel catches on straight away that it's a scam, but he keeps quiet. The two demanding rabbits tell Pipkin they can fly, which leads into a lot of trouble.

Free from Cowslip's warren, Strawberry begins to settle in at the down. Meanwhile, Bigwig hears of a vicious warren called Efrafa and investigates further.

Hazel travels to Nuthanger farm with Pipkin and Fiver to get some new hutch-rabbits to come and join them, in fear that if they don't have enough rabbits living with them they will be wiped out by Efrafa. Hazel heads for trouble involving a man and a gun. They bring back a new rabbit, called Clover.

The rabbits find out the Efrafans have captured Pipkin. Woundwort begins to treat Pipkin well, in order to find out the location of his warren. Meanwhile, Hazel hatches a plan to free Pipkin with help from Campion. They manage to grab as many animals as they can in order to make his plan work, and in the end it works better than they expected.