After two journeys abroad, the fifth Asterix book has our heroes go on a grand tour of their homeland.
Inspector General Overanxius visits the Roman camp of Compendium on Caesar's behalf, determined to subdue the Gauls of Asterix's village. One resounding defeat on the battlefield later, he decides that since they can't be subdued, they should be isolated from the world, and has a giant wall built around the village. Asterix declares that not only will he escape, but also make a tour through all of Gaul, collecting special foods from different spots as evidence; if he succeeds, Overanxius will take down the wall. Accompanied by Obelix, who carries a large yellow shopping bag for the food, and with the rest of the village attacking the wall south of the village as a diversion, Asterix makes his break through the wall north of the village. He and Obelix think little of the Roman soldier on horseback they see riding in the distance as they make their way to Rotomagus (Rouen today).
However, the Roman soldier was a messenger, and the Roman garrison at Rotomagus is expecting the two villagers, who hide in the river and commandeer a pleasure boat being used by a Roman couple to the first stop on their shopping trip, Lutetia, where they buy a hamnote from a pork butcher (and are promptly followed by a small black and white dog). The appearance of a Roman patrol forces them to flee and buy a used chariot from an ancient version of Honest John's Dealership; when it inevitably breaks down, they knock out the Roman driver of a breakdown chariot before he can turn them over to the authorities, and make their way to Camaracum (now called Cambrai) to buy a bag of humbugs.note With help from the shopkeeper, they bash in the Roman patrol waiting for them and go back on the road in the stolen breakdown chariot, where legionary Spongefingus, whose chariot has broken down, mistakes them for the genuine article and unwittingly helps them get past a roadblock. Once he has outlived his usefulness, the Gauls literally cut him loose and head for Durocortorum (known as Rheims today) to buy amphoras of the local wine.note Spongefingus catches up with them, but Asterix pops the cork on one of the amphoras of wine straight into the legionary's jaw, and they are on their way again.
Cutting through the forest, the duo smell roast boar, and come to the house of Unpatriotix, a treacherous Gaul who invites them in, feeds them, and then sneaks off to sell them out to the Romans while they nap. However, Obelix goes out in search of more boars, so that only Asterix is there when the Romans arrive; a panicked Unpatriotix is unable to pack and escape before Obelix returns and shakes Asterix' whereabouts out of him: the nearby town of Divodorum (Metz today). Obelix gets himself arrested by knocking out a legionary and bringing his unconscious body to the jail, and soon, he and a magic potion-strengthened Asterix have broken out and hijacked a Roman postal service cart (sporting the then-modern logo of La Poste, France's postal service) to Lugdunum (today known as Lyons).
Prefect Poisonus Fungus orders his men to stop the two Armoricans when they arrive at Lugdunum, but one of his slaves is a member of the local resistance, and the leader, Jellibabix, ushers Asterix and Obelix down a side road when they find themselves seemingly surrounded by Roman patrols. He leaves them with friends and heads to the prefect's palace, ostensibly to lead him to the two outlaws. However, Lugdunum's streets are a giant maze that only locals can navigate without getting utterly lost, and one quick sprint later, Jellibabix has left the Roman patrol following him unable to find each other or their way out; even the prefect gets lost when a well-meaning legionary picks up the stones he tried to use to mark his route. Jellibabix gives Asterix and Obelix a gift of sausages and meatballsnote and a chariot, and they move on.
Their next stop is Nicae (Nice as it is now known), where, after dealing with uncommonly long traffic jams as seemingly the entire population of northern Gaul descends on the Gaulish Riviera for the beginning of the summer holidays, they buy an amphora of saladnote and begin heading toward their next destination when a Roman patrol spots them. They commandeer the boat of a holidaymaker and row up the coast to Massilia (today called Marseilles), leaving the unfortunate holidaymaker to carry his boat back to Nicae on foot. They stop at an inn to buy fish stew;note the innkeeper, Drinklikafix, is delighted to meet them and he and his regular patrons offer to help them by holding up the Roman patrol hot on their tail with a game of boules.
As Asterix and Obelix head for Tolosa (today called Toulouse), darkness falls, and they rest for the night... only to discover, when dawn breaks, that they have spent the night in the middle of a Roman camp! Deciding that "hitching" a lift with the Romans to Tolosa will speed things up a bit, they turn themselves over to the camp centurion, who, after several failed attempts to put them in chains, takes them to see Prefect Adipus in a cart. When he returns with the prefect, the Armoricans have bashed in his legionaries and left with the cart and some local sausage.note The enraged Romans put a 50,000 sestertii price on Asterix and Obelix' heads, attracting the attention of collaborator Uptotrix in Aginum (today called Agen); he promises the local Roman commander that he will give the two outlaws drugged food and deliver them into the commander's hands. When our heroes arrive, Uptotrix meets them and takes them to his inn, where he first gives them a bag of local prunesnote and then starts serving roast boars to each of them; Obelix begins eating immediately, but a suspicious Asterix forces Uptotrix to eat some of the other boar, and he drops to the floor, fast asleep (Obelix is unaffected; on the contrary, he describes the boar as "a real eye-opener"!).
Leaving the cart behind and continuing on the horses, Asterix and Obelix are forced to stop for the night when Obelix' horse collapses under the weight of his rider and the shopping bag; while they sleep, two bandits steal the shopping bag... and, as they are of similar build to Asterix and Obelix, they are arrested by the first Roman patrol they encounter. They are put on display in the main square in Burdigala (called Bordeaux today) as an example to the locals... only for the real Asterix and Obelix to arrive, reclaim their shopping bag, and bash in the Romans (with help from the locals) before heading on their way with some white wine and oysters.note
They find a ship in the harbour, captained by Seniorservix of Gesocribatum (now called Le Conquet), unloading a cargo of menhirs; Obelix helps them unload in exchange for passage for the two Armoricans back to Gesocribatum (a journey that includes an encounter with Redbeard and his band of pirates, who, in this volume only, include Redbeard's son Erix), where they are smuggled ashore in bags. However, a miscommunication causes them to exit the bags right in front of a Roman patrol, and they are forced to thump their way out of the city and back to their village.
Overanxius is summoned to the village to see the food Asterix and Obelix have brought back with them, but there is one specialty missing: the village's own specialty, which Asterix happily serves to Overanxius... the uppercut. (Obelix, meanwhile, finally notices the small black and white dog that has been following them since they left Lutetia, and takes an immediate liking to him.) The book ends with the usual celebratory feast, which here includes delicacies from all over Gaul in addition to roast boar.
- Badass Boast: Asterix claims they'll not only break though the Roman's attempt to fence them in, they'll go all around Gaul and bring back regional specialties to prove it.
- The Bet: After the Romans try to isolate the Gaulish village, Asterix makes a bet with Overanxius that the latter will go back to Rome and raise the siege if Asterix and Obelix succeed in making a tour through all of Gaul.
- Bowdlerization: In the British album release, Obelix mishears the town name Divodorum and responds that he doesn't care that Unpatriotix has "ordered rum". In some releases such as the Young Telegraph print it's "ordered a drum" instead.
- City in a Bottle: The Romans intend for the Gaul village to become this, building a huge wall to isolate them from the rest of the world. It is what prompts Asterix and Obelix to go on their quest.
- Les Collaborateurs: Although Unpatriotix of Divodorum is an opportunist who needs the money he would get for selling out Asterix and Obelix, Uptotrix of Aginum is firmly in league with the Romans, and makes advance plans to drug their food and deliver them to the local commander. However, the drugs don't work on Obelix, and Asterix forces the collaborator to eat some of his boar after becoming suspicious.
- Continuity Nod:
- As Asterix makes the wager with Overanxius, Obelix asks him to give their regards to Caius Fatuous, the unscrupulous gladiator trainer from Asterix the Gladiator, upon his return to Rome.
- When Asterix and Obelix arrive in Lutetia and find the roads ensnared in one giant traffic jam, they note that things haven't been sorted out since their last visit in Asterix and the Golden Sickle.
- Hero Stole My Bike: Asterix and Obelix hijack several boats and carts on their way around Gaul; while most of the vehicles belong to the Romans, the rowboat they commandeer to get from Nicae to Massilia has been hired by a fellow Gaul, who then has to carry the boat over land back to Nicae (nearly 100 miles!).
- The Highwayman: Asterix and Obelix become victims of two of them while they are sleeping.
- Historical In-Joke: A native of Massilia (Marseilles) threatens a Roman patrol not to disturb their bowling game or else there will be blood on the streets, riots, revolution - "we're thinking of writing a song about that".note
- Honest John's Dealership: A used chariot dealer sells Asterix and Obelix a spanking-new ride with a strong black stallion... only problem is, the chariot falls apart within a few minutes, and the strong black stallion turns out to be a sickly white horse painted black, its paint washing off when it starts to rain.
- Huge Rider, Tiny Mount: Obelix becomes this when he and Asterix ditch their chariot and ride on the horses themselves in order to make more progress. And since Obelix insists on also carrying the bag, it doesn't take long for his horse to collapse of exhaustion.
- Lost in Translation: One of the reasons Asterix and the Banquet was the fifth Asterix book to appear in French but the twenty-third to appear in English was the translators' concern that the jokes based on French regional stereotypes (such as the inability of Normans to give a straight answer, the absurdly labyrinthine nature of Lyon's streets, the impossibly long traffic jams which stretch back from the Côte d'Azur at the beginning of every summer, the hot-blooded nature and penchant for exaggeration of the locals in Marseille, etc.) would make little sense to audiences outside France.
- Meaningful Name: The two treacherous Gauls that try to sell Asterix and Obelix out to the Romans are named, appropiately, Unpatriotix and Uptotrix.
- Mistaken Identity: Two robbers come across the sleeping Asterix and Obelix, and steal their bag containing all the items they collected so far. Unfortunately for them, since the robbers' physical stature matches that of Asterix and Obelix (a short guy and a tall fat guy) and since they now have the bag, the Romans mistake them for Asterix and Obelix and promptly arrest them.
- National Stereotypes: Well, regional stereotype: The Massilians are a walking Cliché Storm (Funetik Aksent, lazy, tend to exaggerate, play pétanque, hold non-southerners to be a bit odd, etc.).
- One Steve Limit: Averted; the owner of the Massilian inn where Asterix and Obelix stop is named César (the French equivalent of "Caesar"), leading to a surprised reaction from the two heroes upon hearing another patron call his name.
- La Résistance: Although there are Gauls in almost every city our heroes visit who help them score points against the Romans, Lugdunum stands out as having a whole network of resistance fighters doing what they can to undermine the Roman presence in the city; they even have at least one man on the inside, a slave at the prefect's palace whose comings and goings are completely ignored by the Romans.
- Running Gag: Dogmatix, who is not yet given a name here, serves as a literal Running Gag; from his first apperance in Lutetia, he keeps following Asterix and Obelix wherever they go, but they never notice him untill the very end of the story.
- The original French title (Le Tour de Gaule) and the central plot are allusions to the Tour de France, with Obelix's bag referencing the yellow jersey worn by the leader.
- The locals Asterix and Obelix meet in Massilia are homages to the 1930s Marcel Pagnol stage play-film trilogy Marius, Fanny, and César; innkeeper Drinklikafix in particular is drawn to look like Raimu (stage name of Jules Muraire), the actor who played the third film's title character (also an innkeeper by the port in Marseille in the plays and films) throughout the trilogy, which is why he is initially addressed as "César" by the patrons. The scene of the regulars playing cards is framed to look like a similar scene from Marius, while their boules game visually references Fanny.
- Symbol Swearing: Prefect Poisonus Fungus of Lugdunum unleashes a storm of this when a legionary tells him he's been picking up the stones he was dropping to mark his route through the city streets, thereby making him as lost as the other legionaries.
- Tampering with Food and Drink: Twice in the story, a fellow Gaul betrays Asterix and Obelix by putting a sedative in the wild boar he serves them and then sells them out to the Romans. The first time it works on Asterix and he is arrested, but Obelix frees him later. The second time, Asterix realizes something is up and forces his host to eat the boar instead, confirming Asterix' suspicions when the host promptly falls asleep. Obelix does eat his boar, but somehow the sedative doesn't work.
- Unwanted Assistance: The prefect drops pebbles behind him so he won't lose himself in The Maze that is Lugdunum. A legionary notices his boss is spilling pebbles everywhere and helpfully picks them up.
- Vacation Episode: Asterix and Obelix travel to various cities in Gaul, aka France.