We open in the Gaulish village, where a miscommunication between Vitalstatistix and his shield bearers leads the irate chief to give them the sack and appoint Asterix and Obelix their replacements; the fact that their difference in height means they cannot hold him even close to level leads him to dismiss Asterix and have Obelix hold him on his own, as if he were serving drinks in an inn.
Meanwhile, local Roman governor Varius Flavus is spending most of the taxes, fines, and licence fees he collects from the locals on lavish orgies at his palace in Condatum (now called Rennes), but the suspiciously low sums he sends back to Rome are starting to attract suspicion, and Caesar sends a Quaestor (inspector) named Vexatius Sinusitus to investigate. Sinusitus asks for a bowl of vegetable soup before he goes to bed for the night, planning a thorough audit of Flavus' books for the next day, but Flavus poisons the soup, and Sinusitus is quickly taken gravely ill (not helped by Flavus' in-house doctors, a gaggle of argumentative quacks). Sinusitus gets rid of them by asking them to make an offering to Apollo so that he can secretly ask his bodyguard/driver to fetch the druid Getafix, whom Caesar has mentioned during his epileptic rantings.
Bound always to help the sick, Getafix goes to Sinusitus accompanied by Asterix and Obelix (who takes the instruction to "drop everything" literally, with unfortunate results for Vitalstatistix). He soon realises what has happened, though he keeps this detail from Flavus. Getafix can cure Sinusitus, but the cure requires the silver star (now known as the edelweiss), a rare flower that grows only at very high altitudes, and so the druid dispatches Asterix and Obelix to Helvetia (or Switzerland as we call it today) to find one. In the meantime, Sinusitus will go back to the Gaulish village, supposedly as a hostage to ensure Asterix and Obelix's safe return, but actually to get him away from Flavus and encourage Flavus to target Asterix instead. It works, giving Flavus an extra reason to want to stop Asterix, and he sends his deputy Caius Eucalyptus to Genava (now spelled Geneva), the capital of Helvetia, to ask the local governor Curius Odus (an old friend, and equally corrupt) for help.
Eucalyptus arrives in Genava ahead of the Gauls, and Odus sends orders to have them stopped at the border. However, the border guards make the unwise decision to accept Asterix's offer to "demonstrate" the contents of the gourd of magic potion Getafix gave him for the journey, and the two Gauls cut across country and swim across the lake known today as Lake Geneva at night to get into the city undetected. En route, they run into Malodorus Caseus, a friend of Odus' who was thrown into the lake for losing his bread three times at Odus' fondue orgy, and take rooms at a nearby inn.
Caseus' return to Odus' palace alerts him to the Gauls' presence in Genava, but the innkeeper, Petitsuix, covers for them when the Romans come knocking, and when they are gone, he wakes our heroes and persuades his banker friend, Zurix, to let them sleep in one of his safes overnight (after first opening an account attached to the safe). However, the Gauls are hungry, and Obelix smashes the door off the safe from inside so that they can ask Zurix for food; when the banker sees the smashed safe door, he is horrified, and even more horrified when Odus' legionaries come knocking. He quickly rushes them into another safe full of Egyptian souvenirs - which turns out to belong to the centurion leading the patrol at the door! The sight of the Gauls' smashed safe door prompts him to vow to return the next day to close his account, reducing Zurix to a sobbing wreck, but the Gauls have avoided capture again.
Petitsuix picks up the Gauls the next day and gives them each a Paper-Thin Disguise to make them look like locals on their way to perform their annual national service commitments. However, the Romans have set up roadblocks, and Caseus recognises the Gauls; Petitsuix leads them into the meeting of the International Conference of Tribal Chiefs, and they hide in the audience by pretending to be asleep (not even pretending, in Obelix's case), but this ruse only works for a few minutes, and soon they are on the run again - or on the swim again, as they jump back into the lake, followed closely by the Romans. The Gauls and Petitsuix are picked up by a group of Helvetians on their way to national service camp for some games, food, and drink, while the Romans report back to Odus, who has all available troops dispatched to the camp to get the Gauls, dead or alive.
As Petitsuix parts company with the Gauls and heads back to his inn, Asterix and Obelix are finally at the foot of the Swiss Alps, but cannot begin climbing until after the Helvetians have finished their sport, food, drink, and singing (yodelling, which initially horrifies Obelix so much that he jumps back into the lake and tries to swim away). Time is running short, however, so Obelix downs the cheese fondue without even bothering with bread, then empties an entire barrel of wine into his mouth and passes out drunk after five seconds of attempts at yodelling. With the Romans descending on the camp, Asterix and a group of Helvetians tie themselves to each other and to Obelix and begin climbing the mountain while the other Helvetians fend off the attacking Romans using the last of Asterix's potion mixed with more fondue cheese. An overeager legionary grabs the unconscious Obelix, but is pulled up and out of reach before his comrades can catch up with him, and ends up getting dragged up the mountainside, desperately trying to keep Obelix from waking up and alerting the others to his presence.
Asterix finally finds a silver star blooming near the top of the mountain, and after picking the flower, he and the Helvetians continue to the summit (where they finally discover the now thoroughly fed up legionary). Asterix begins to drag the still unconscious Obelix back down the other side of the mountain to Gaul, but Obelix slides under him, and Asterix ends up on a runaway toboggan ride atop his friend, knocking Odus' centurion flying when he tries to stop them (and making the Roman wish he was back in Egypt). When they get below the snowline and come to a stop in yet another lake, Obelix finally regains consciousness, and he and Asterix take the silver star back to their village.
Back in the Gaulish village, Varius Flavus arrives to pretend to be upset about Asterix and Obelix not getting back and the Gauls having to kill their hostage — at which point a fully-cured (and magic potion-strengthened) Sinusitus emerges from Getafix's hut and punches Flavus into the sky, telling him that, when he lands, he'll be thrown to the lions along with Curius Odus. Vitalstatistix, now being carried by Geriatrix and Fulliautomatix (and so still tilted at a 45-degree angle), gives Sinusitus the honour of being the first-ever Roman to join the Gauls at their traditional banquet. Obelix, meanwhile, gives Getafix his impression of Helvetia: "Flat."
- Artistic Licence - Geography: An In-Universe case: As Obelix was dead drunk during the entire mountain-climbing sequence, he has a somewhat skewed view of the terrain:Getafix: So, Obelix, what's Helvetia like?
Obelix (sweeping his arm horizontally): Flat.
- Bamboo Technology: The "Cuckoo" clocks, which consist of hourglasses and an innkeeper yelling "CUCKOO!" every hour, forcing the guests to wake up and turn over their hourglasses.
- Big Eater: Most of the Romans, who are eating incredibly rich food such as boar's tripe fried in aurochs' dripping and served with honey, and cheese fondue.
- Big Guy, Little Guy: Obelix and Asterix's respective matching of these descriptions is played up in the opening sequence after Vitalstatistix sacks his shield bearers and "awards" our heroes the "honour" of replacing them. Since Asterix is only half Obelix's height, Vitalstatistix ends up tilted at a 45-degree angle and struggles to remain standing, to the loud laughter of the other villagers. (At the end of the book, Geriatrix and Fulliautomatix have been forcibly drafted into the roles, with similar results for the same reason.)
- By-the-Book Cop: Sinusitus. As a Quaestor (the beginner rank in the cursus officium), his job was tax control, and to investigate corruption (and also murder), so he's exactly this. In modern-day Italy, questore is an actual police rank.
- Comically Inept Healing: The physicians of the Roman garrison that Flavus has on call are all hopelessly incompetent (one proposed treatment even includes the phrase "if the patient survives...") and prone to arguing over who is the best suited for the operation. In Flavus' words, "when they get together, they're more murderous than a legion armed to the teeth." Of course, Flavus didn't want Sinusitus to recover, so from his perspective that was a good thing: either none of their "cures" would work, or they would inadvertently kill Sinusitus with their bungling.
- Continuity Nod:
- Geriatrix still has the club he took from Magnumopus in the climactic battle in the previous album, Asterix and the Roman Agent.
- When Sinusitus relates the story of his journey from Rome to Varius Flavus, he mentions that he ran into a band of pirates - implied to be Redbeard and his crew - but had nothing to worry about from them, as they started arguing among themselves and scuttled their own ship. Evidently the breakdown in camaraderie sown by Convolvulus in the previous volume hasn't healed yet.
- Cool and Unusual Punishment: Lose your piece of bread in the cheese fondue once, and it's five of the best with a stick. Lose your piece of bread twice, and it's twenty lashes with a whip. Lose it three times, and it's into the lake with weights tied to your feet. The orgygoer who keeps losing his piece of bread, Malodorus Caseus, seems almost as delighted as his fellow revellers when he incurs these punishments.
- Corrupt Politician: Varius Flavus, who collects a fortune in taxes, only to divert them to his personal hoard and spend the remainder on orgies, while sending just a few pieces of gold to Rome. To a lesser extent, Curious Odus, who doesn't seem worse than most of the other Roman authority figures seen in the series, but is quite willing to be part of the plan to kill Sinusitus.
- Covered in Gunge: The people attending the orgy become increasingly covered in a thick blanket of melted cheese.
- Cuckoo Clock Gag: With the story being set in Switzerland, naturally a gag about cuckoo clocks was inevitable, but with a twist since actual Cuckoo Clocks had not been invented yet in the time the story is set. Instead, we see an Innkeeper who loudly yells "Cuckoo!" every hour, signaling his guests that they have to turn the hour glass next to their beds.
- Excuse Plot: The entire premise - getting an alpine flower for a cure - is simply an excuse for making as many Switzerland jokes as possible within the course of the plot.
- Flower from the Mountaintop: Asterix and Obelix have to pluck one. The flower is of course edelweiss.
- After swimming and climbing a mountain to get Asterix and Obelix one Roman complains about doing all these activities. His centurion snaps back: "We're not taking a holiday here." Amusing, because today both swimming and mountain climbing are holiday activities in Switzerland.
- When Asterix uses Obelix's body to slide down the snowy mountain he references another popular Swiss sport and holiday activity: snow sliding and/or skiing.
- The Ghost:
- Redbeard and his band of pirates have this role in the story. They don't appear on panel, but are mentioned by Vexatious Sinusitus; apparently, they attacked his ship while he was on his way to Gaul, but fortunately got into an argument with each other and sank their own ship.
- Caesar also has this role. He doesn't appear in the book, but he dispatched Sinusitus to look over Flavus' books off-panel, setting the story in motion.
- Heavy Sleeper: Obelix misses most of the excitement, sleeping through climbing a mountain and several battles due to him drinking a whole barrel of alcohol. His description of Helvetia after the fact is "Flat."
- Intimidating Revenue Service: Sinusitus, causing Flavus to use poison in an attempt to avoid the impending audit. Atypically for this trope, Sinusitus is portrayed as just an honest official trying to do his job, and Flavus genuinely was doing things that were grounds for an audit.
- Megaton Punch: Flavus gets his just desserts from the magic-potion enhanced Sinusitus.
- Murder Is the Best Solution: When asked what he'll do if Rome sends someone to investigate his finances before he has a chance to cut and run, Flavus says he'll either corrupt the man or kill him. Sinusitus shows no interest in worldly pleasures, so Flavus quickly goes to Plan B.
- National Stereotypes: The Helvetians (Swiss) are portrayed as punctual, obsessed with keeping everything clean, and very good at banking. They are also seen playing Alpine horns, yodeling and eating cheese.
- Neat Freak: Most Swiss people shown, something that many would call Truth in Television. When a Roman gets thrown into the lake their first concern is that the lake is very muddy at this time of year.
- Neutral in Name Only: In Asterix in Switzerland, the neutral Helvetians' (modern-day Switzerland) idea of neutrality is beating up the Romans and then bandaging them (a Shout-Out to the Red Cross organization).
- Oh, Crap!: Flavus has a fairly spectacular one when he realises Sinusitus has been cured.
- Ornamental Weapon: Averted. Although Asterix does not use his sword as a weapon here, it proves to be a useful tool for climbing mountains.
- Paper-Thin Disguise: Petitsuixs idea of disguises are...just bows and arrows to carry. Unsurprisingly, it doesnt work.
- Play-Along Prisoner: Getafix demands that Sinusitus be kept at their village as a 'hostage' for Asterix and Obelix's safe return. Flavus naturally assumes that having our heroes come to a sticky end will mean that the Gauls will kill Sinusitus in retaliation, but it's actually to forestall any further attempts to kill him (though he points out Asterix and Obelix need to move fast as it's a lethal poison and Sinusitus's already-slim chances for survival hinges entirely on how quickly the heroes can retrieve ingredients needed for the only cure to it).
- Poison Ring: Varius Flavus has so many of these (and has apparently used almost all of them) that he has trouble finding the still-loaded one.
- Pragmatic Villainy: Eucalyptus objects to the tax skimming, not for the illegality of it, but because the scale of it had reached the point where they were in danger of facing an outside audit and getting caught.
- Punny Name: Par for the course for the Asterix series, but the name of the guest at Curius Odus' orgy who keeps losing his bread in the cheese fondue stands out: Malodorus Caseus, which is dog Latin for "stinky cheese".
- Reasonable Authority Figure: Sinusitus, excluding Caesar, the first honest, upright and truly incorruptible Roman official in the series. Even Vitalstatistix is impressed enough by Sinusitus to invite him as their first Roman guest in their traditional banquet.
- Running Gag:
- Every time the possibility of eating boar's tripe fried in aurochs' dripping is mentioned, someone will excitedly ask, "With honey??" At one point, one of Flavus' guards falls into a cauldron of cold boar's tripe fried in aurochs' dripping, and as he eats the contents, he asks if anyone has a spot of honey.
- Whenever the locals see anyone swimming across the lake, they point out that the bridge that Julius Caesar had destroyednote has been re-built, and they should have taken that instead. Eventually, a Helvetian fishing on the lake mutters that they should probably put up a sign about the bridge.
- Save the Villain:
- Getafix decides to help cure a poisoned Roman, despite the fact that Romans are usually their enemies, on the grounds that he is honour-bound to help anyone who needs his services.
- It should be pointed out that Getafix stays neutral throughout the series on who deserves his services. He has been known to provide treatment and assistance to Romans (and adversaries) with legitimate or honourable needs while denying his own villagers and countrymen who have selfish agendas.
- A Swiss beats up a Roman, then gives him medical aid afterwards, because even their enemies should receive medical help (a reference to the fact that the Red Cross was created by Swiss Henri Dunant).
- Even Obelix checks the pulse of a legionary he's just knocked out.
- Getafix decides to help cure a poisoned Roman, despite the fact that Romans are usually their enemies, on the grounds that he is honour-bound to help anyone who needs his services.
- Asterix and Obelix have their tire changed by Antar, the mascot of the French service station Antar. In the English version, it is changed by Bibendum, the Michelin Man himself.
- The orgy scenes at Varius Flavus' palace in Condatum are a spoof of similar scenes in Federico Fellini's film Fellini Satyricon.
- Skewed Priorities: The Swiss characters are very much obsessed with cleanliness (when a Roman loses his third piece of bread and is thrown in the lake, they comment that it's barbaric- the lake is very muddy at this time of year, Petisuix has to sit down after deliberately tracking mud through his inn to allay Roman suspicions) and timeliness (Petitsuix runs back to his inn every hour to yell "Cuckoo!").
- Slimeball: Varius Flavus is simply one of the most odious Romans in the entire series, a decadent, hedonistic, bloated and greedy monster concerned only with embezzling as much money as he can to fund his parties, thinks nothing of casually poisoning anyone who threatens his way of life, and looks somewhat like a toad.
- Suspicious Spending: Varius Flavus' being able to host non-stop orgies while simultaneously only being able to raise a pittance in tax revenue to send back to Rome gets Sinusitus sent to Condatum to look over his books. Eucalyptus actually warns him that the obvious disparity between what Flavus is spending on parties and what his district is allegedly able to afford is likely to get a Quaestor sent their way.
- Swiss Bank Account: Where Asterix and Obelix spend the night without being bothered by Romans. Obelix's usual approach to enclosed spaces results in a vault door being ripped off his hinges, causing a Roman centurion to declare he's closing his account if the security is that bad (and sheepishly justifies his having a Swiss Bank Account to his underlings).
- Take That!: The palace of international conferences where Asterix, Obelix, and Petitsuix hide from the Romans is a reference to the various international peacekeeping organisations with headquarters in Geneva. Given that the floor is held by a delegate giving a long-winded speech that has bored most of his audience to sleep, we may conclude that Goscinny and Uderzo were not impressed by such organisations! Or just political organisations in general.
- Tampering with Food and Drink: Varius Flavus poisons Sinusitus's vegetable soup to keep him from discovering how much he has been skimming off the top of the taxes he is supposedly collecting for Rome.
- Unexpectedly Dark Episode: Not that the album doesn't contain the usual Asterix humor, but this story has one of the more darker plotlines of the Asterix series for the following reasons:
- Asterix and Obelix have to go on their quest to save an innocent man from assassination by poisoning.
- The fact that two of Varius Flavus' poison rings turn out to be empty heavily suggests this isn't the first time he disposed of an opponent in this manner. It's a chilling thought, considering how much power a Roman elite has to subvert and undermine Rome's system of checks and enforcement.
- Although it is not shown, it is heavily implied Flavus and Odus will meet their deaths once Sinusitus exposes their corruption.
- On a more meta level, it exposes the corruption and decay creeping through the Roman Republic (and later, Empire) and its elites, no doubt caused by long periods of peace and stability.
- Vacation Episode: Asterix and Obelix travel to Helvetia, aka Switzerland.
- What Happened to the Mouse?:
- While it's mentioned that both Varius Flavus and Curious Odus will have their day in the Circus over their actions, no mention is made of Flavus' tax collector Caius Eucalyptus, who was very much in on the scheme and disappeared from the story at the halfway point. Granted, Eucalyptus did seem smarter than his boss (in particular, warning him that Rome might get a bit suspicious if he carries on holding huge orgies while claiming to earn no money), so he may have taken more care to hide his misdeeds and hightail it out of there once the game was up.
- Sinusitis's guard is also missing from the scenes at the end of the story. Presumably, he was sent to report back to Rome about the poisoning, but it isn't stated anywhere.
- William Telling: Asterix does some archery and hits a bulls-eye, just narrowly missing an apple balanced on a boy's head. Spectators were impressed, but felt something was missing.
- Windbag Politician: The peacekeeping conference is a bunch of tribal chieftains speaking in turns to wake up all the others.
- Yodel Land: A very romanticized version of Switzerland is shown here, with all the Alpine clichés (except chocolate) thrown together.
- These Helvetians are crazy!