Toad is excited about celebrating New Year's Eve at Toad Hall - too excited to listen to Badger's discovery that a railway is going to be built through the area. Badger is also worried about the dilapidated state of Toad Hall, but Toad is too busy with his bagpipes. Just before midnight Toad goes outside and waits to let in the New Year. However, he cannot get back in the front door so he goes through a disused door to the coal cellar. He becomes lost in his own network of hallways. Meanwhile, the weasels invite themselves to the party and steal lots of food. Toad ends up falling down a chimney and lands in a pile of soot at the party, just in time for him to present his Robert Burns poem.

Badger is still concerned about the proposed railway, and about the disrepair Toad Hall has fallen into. He tells Toad about the architect Inigo Toad, who was a royal favourite. Toad is taken by the idea of improving his home and draws up plans for a new wing. Rat and Mole inspect the designs and discover, among other problems, there are no doors. Badger is confident that no builder would touch the plans. However, the weasels set themselves up as builders and agree to Toad's instructions. The only difference they make to Toad Hall is to un-clutter it, by taking all the furniture back to their den. Badger manages to talk them out of their contract.

Rat returns from staying at Mole End to discover that the river is gone. The riverbed is completely dry. Badger can offer no explanation, so they set off searching for an answer. Rat and Toad walk along the riverbed until they eventually come across some field mice. Their caravan has been flooded out by the diverted river. The field mice have to stay at Toad Hall and cause havoc as they play. Otter discovers the cause of the river problem - the water was dammed and the water pumped out so that a pier could be built to support a railway bridge. The river is soon allowed to run again, but the railway still approaches.

After reading A Boy's First Book of Wonders, Toad is seized by the idea of hosting a medieval joust. He issues an open challenge, offering to pay ?100 to anyone who can beta him. Alfred refuses to take part in the joust, so Toad decides to ride on his motorbicycle instead. On the day of the medieval pageant, Toad gives a speech and asks for challengers. The Chief Weasel accepts, riding on a chariot pulled by his henchman. Toad cannot control his motorbicycle and runs amok, but manages to keep his prize money. Hanging at the top of the jousting stick has given him a new idea - he orders a hot air balloon.

A newspaper report on an archaeological discovery made while building the railway tells Badger just how close the railway is. Toad is more interested in the famous archaeologist who made the discovery, Lord Rushton, and also wants to be made into a Lord. He begins excavating in his front lawn, and invites his friends and the King to the opening of his new museum. However, the day before the opening he still hasn't found a thing, so he buys 'artifacts' off the weasels. The King fails to attend the opening, but it still proves to be a memorable occasion. Toad presents the Roman drinking cup (broken flowerpot), the Viking stirrup (tool handle), the Pharaoh's scepter (edging tool) and the 600 year-old shield (rubbish bin lid).

Toad's hot air balloon finally arrives, and despite Rat's criticism of Toad, Badger thinks it will be a good way to survey the approach of the railway. However, when Toad packs a huge hamper to take up with him, only Mole is left to help. The henchman weasel has fallen asleep in the basket, and as Mole tries to carry the hamper he trips over the rope and the balloon begins its ascent. Mole drives along in Toad's car, following the balloon across the countryside. Up in the air, Toad takes photographs of the railway as the henchman tries not to be sick. With too much weight, the balloon starts drifting downward towards a lake. With all the sandbags released, Toad and the henchman fight over who should jump out. Toad pulls the wrong lever and the balloon crashes down into a tree. Examining the developed photographs, Badger is pleased with Toad's efforts. However, Mole seems to have been struck down with motoring insanity...

The four friends have gone on a long walk to observe the development of the railway. Toad lags behind and his friends tell him that he he is unfit and overweight. Toad orders a large selection of exercise equipment from a magazine and begins training. He is punched in the nose by his own punching bag and injures his foot. Mole and Rat visit and watch Toad demonstrate the various apparatuses. He eventually gets knocked over, taking a desk with him, spilling papers and letters onto the floor. Badger discovers the nature of the letters Toad hasn't bothered to read. One informs Toad that, as a landowner, he is entitled to complain against the proposed railway route. However, the period set aside for such action has already expired. Badger has nothing to say to Toad.

Badger goes to London, leaving Rat and Mole to keep an eye on Toad. As soon as the weasels discover Badger is going away, they disguise themselves as the railway company's solicitors and pay a visit to Toad Hall. Filling Toad's head with adventurous ideas, they manage to talk Toad into selling his home. When Badger returns he finds out what has happened, and takes a look at the contract. Toad signed it without reading that it gives Toad Hall to the weasels. Badger confronts the phony solicitors and talks them out of the deal.

Everyone is busy preserving foods for the winter except Toad, who plans to just pop into London and pick up a hamper. He gives away all the produce from his garden to his friends. Toad sees an advertisement for the Buffalo Patent Canning Machine, similar to the one used on Arctic expeditions, and orders one. Much to Badger's disgust, he has to buy produce from London to put into the cans/tins. Ignoring Rat and Mole's food safety advice, he cans/tins a variety of foods and invites his friends over to dinner to try them out. When he opens the first can, the rotten contents spray out all over his face. The party breaks up when the other cans start exploding.

The young field mice are getting excited about Halloween, but not as much as Toad. He makes a spectacular mask and costume to wear at the party he is hosting. On Halloween night the field mice arrive at Toad Hall very frightened, saying they have seen a monster in the Wild Wood. After they help him take off the mask that has become glued to his face, Toad leads them back to the scene where he too sees the glowing eyes and hears the growl. The next morning Badger comes to visit the bedridden Toad and tells him that the monster was in fact a steam traction engine from the railway company. Toad pretends that he knew all along.

The railway is now so close that Badger can hear trees being felled from outside his house. Nonetheless, Toad promises to put on a fantastic display of fireworks for Guy Fawkes Night. After an unsuccessful attempt at making his own, Toad buys a great quantity of expensive fireworks, only to have them stolen by the weasels. Everyone is enjoying a quiet gathering with baked potatoes and treacle toffee when suddenly rockets whiz up from the Wild Wood. Not only do the weasels put on the display, they set the Wild Wood on fire and burn themselves out of house and home.

Mole is dressing for Toad's Christmas party when his home starts shaking with an earthquake. Running outside, he learns that young Billy Rabbit has become trapped in a tunnel. With the help of Rat, Mole digs out Billy and takes him to the party. Meanwhile, Badger has been left alone with Toad at Toad Hall, wondering what has become of the others. When they finally arrive, Toad presents the world-famous magician "Il Mysterioso". Jeered by Rat, Toad, er, "Il Mysterioso" performs a variety of amazing tricks that leave the audience gasping for breath between laughs.

The railway is about to destroy everything and Badger has given up. Toad has everyone, including Mole's cousin Auberon, over for New Year's Eve anyway so that he can perform his poems and play his bagpipe. The gathering is interrupted when the henchman arrives with awful news. The weasels were stealing a traction engine from the railway company and driving it through the Wild Wood when the ground underneath gave way and swallowed up the engine and the weasels. Rat insists that they go to the Wood to help, but when they get there there are no signs of life. The group returns to Toad Hall to find an old acquaintance waiting for them on the doorstep with an important message...