ROME—It was really too good to be true. After months of a draconian lockdown, a group of about a dozen twentysomething Italians decided to meet up “somewhere safe” for their long awaited—and much deserved—summer holiday reunion. The gang met in Sardinia, one of Italy’s regions with the lowest number of COVID-19 cases. What could go wrong? 

Everything, it would seem.

The group wound up spending the weekend of Aug. 15 at the Country Club of Porto Rotondo on Sardinia’s Emerald Coast where a friend from Milan was a DJ. After a few days of partying and dancing, they went club-hopping around the area and returned to Rome a few days later. What they didn't know was that the DJ was an asymptomatic carrier, and that they were super-spreaders. 

Now, four of the 20-year-olds on that fabulous weekend getaway are in Rome's Spallanzani Infectious Disease Hospital and 30 percent of all new infections coming onto mainland Italy originated in Sardinia, once a safe haven. 

Stories like this are frequent across Europe. There is the case of 19 teens who came back to their home town on Lake Como after sailing in Croatia who all tested positive, and there is the U.K.’s whack-a-mole approach to quarantines that defies logic even in the uncharted waters of a pandemic.

Now, the U.K. announced that Croatia would be on their red list within 24 hours, meaning anyone coming in from that country has to quarantine for two weeks. The U.K. did the same last week to France, sending tens of thousands of British tourists into a frenzy either trying to get back home quickly or jumping to a country that is still greenlighted in the U.K. like Portugal, which is expected to get back to green and thus be flooded by Brits.

Italy has so far dodged the worst of what for all intents and purposes is the second wave of Europe’s COVID-19 pandemic. Cases have doubled in the last seven days, but the number of new daily cases has yet to hit 1,000 in a 24-hour period, though it did edge close to 900 on Thursday. Health experts say that’s because masks are required in public spaces across the country, as they have been since the lockdown ended in May. 

But in other countries that were far behind Italy’s epicenter status last spring, the story is very different. In Spain and France, where mask requirements have only been put in place in the last few weeks, the new cases are surging, sometimes above 3,000 each day. Germany, too, has hit a new 24-hour post-lockdown record with more than 1,500 new cases. Ireland is also seeing a surge, with their health minister threatening a full nation lockdown if the numbers keep climbing. Even Greece, once the shining example of how to keep the numbers down, has just required face coverings on the beach island of Mykonos, which should make for some interesting tan lines. 

Croatia, which is the only European country to have allowed Americans to enter without quarantine, has now seen a tripling of its contagion rate.

In Italy, the threat of another lockdown is enough to make people pay attention. Nightclubs and discotheques were shuttered over the weekend and face coverings are now required in all outdoor places where people gather from 6 p.m. to 6 a.m. until the foreseeable future.

Walter Ricciardi, Italy's “Dr. Fauci,” and chief consultant to the health ministry, says lockdowns are inevitable if the numbers continue to climb. “Italy is at a crossroads right now,” he told the Guardian this week. “If we do not apply containment measures and the numbers continue to rise, localised lockdowns will be required.”

Already, any visitors to Italy landing from Greece, Spain, Malta, and Croatia are met with a swab up their nose at the airport, which has proven effective in finding dozens of new cases. But it's the clusters that worry people the most. On the island of Santo Stefano off Sardinia, around 470 people are under quarantine in paradise after a 60-year-old employee at the posh resort tested positive. Where the next cluster erupts is anyone's guess.

While most of the cases in Europe right now are tied to travel, they aren't all being imported from abroad. Dr. Massimo Galli, an infectious disease specialist who has been a voice of sanity during the pandemic, told The Daily Beast that while travel is a problem, it is not the only threat. “It is easy to get distracted and assume the new cases are all from travelers,” he said. “But instead it is more of a false sense of security we have after surviving the lockdown, as if we’ve done enough and now it's gone—it's simply not.”

In September, Europe will face a new challenge as millions of school children mask up to go back to school. If the virus spread isn't mitigated by then, the new year will likely look very much like the old year. The Italian government has vowed that a nationwide lockdown isn't in the cards, though has suggested regional lockdowns or even closing off certain sectors of the economy will happen if things get worse. Across Europe, experts are struggling to define what's happening, whether it is part of the original wave or a whole new phase of the pandemic. One thing’s for sure, the median age of those infected is now below 40, where the original outbreak hit those above 60 hardest. That may mean it will be harder to control but easier on the health-care systems. Either way, it's not over yet.