At 10 pm on New Year's Eve, an unidentified British teenager got off a train in Cologne, Germany, with her boyfriend and began walking to the square just outside the train station, when she saw something unusual.
"I felt afraid the moment I saw the strange behavior of the people around me," she told the BBC. "The main station was full of wobbly teenagers and young adults, of all ages, some possibly below 18, very drunk and unaware of their whereabouts."
What she saw has since become a national scandal in Germany: Hundreds of men gathered in the square that night were encircling small groups of women, robbing and, often, sexually assaulting them.
"Someone had his hands between my legs, but we managed to get away before anything worse happened," another woman, referred to as Anna, told Deutsche Welle. When she went to notify police, she saw she had been far from alone: "There were lots of girls, all crying uncontrollably."
German police now say they're investigating 516 criminal complaints, 40 percent of which relate to sexual assault.
But the incident has become a major controversy for two distinct yet overlapping reasons. The first, and most obvious, is women's safety: How did this happen, and why couldn't police stop it?
But it's the second that has become most politically charged: Cologne's police chief described the attackers as "Arab or North African" in appearance — and out of 32 suspects so far identified by federal police, 22 are asylum seekers — thus touching on Germany's already sensitive and fraught debate over refugees and migrants.
The uproar over Cologne has become a debate about immigration and what Germans typically refer to as the policy of "multiculturalism," with long-simmering German skepticism and wariness over migration now boiling over into a national controversy.
How police lost control in Cologne
Cologne's police, according to an internal Cologne police report obtained by Der Spiegel, hadn't expect a major incident at the Cologne train station square, and, unprepared, were quickly overwhelmed.
The outnumbered officers focused on breaking up ongoing assaults rather than attempting to apprehend anyone — and even then were met with violence. According to the author of the Cologne police report, officers were met with a level of resistance "like I have never experienced in my 29 years of public service" and were "bombarded with fireworks and pelted with glass bottles."
The report indicates that police believe the crowd consisted largely of migrants. (German officials have since urged citizens not to assume that assailants are refugees or migrants based on their appearance, noting that some may for example be German citizens of North African descent.) When the incident ended, police had not yet detained a single person, apparently too focused on trying to instill order.
As a result, we're left with basically two theories as to how something on this scale could have happened; comments from German authorities suggest either could be true.
The first theory is that the attack was spontaneous: A crowd of men were drunk and angry, and mob will took over.
"After the intoxication with drugs and alcohol came violence," Ralf Jaeger, the interior minister for North Rhine-Westphalia (the German state that includes Cologne), said in a Monday hearing. "It culminated in the acting out of fantasies of sexual omnipotence. That must be severely punished."
The other theory is more ominous: that the attacks were planned and coordinated.
"My suspicion is that this specific date was picked, and a certain number of people expected. This would again add another dimension [to the crimes]," German Justice Minister Heiko Mass told the newspaper Bild am Sonntag.
On January 8, Cologne's chief of police was forced to resign.
"The events in Cologne have profoundly changed the dynamics of Berlin politics"
"Rarely in recent memory has a single event captured the German conversation quite like the Cologne attacks," German columnist Anna Sauerbrey writes in the New York Times.
Merkel's government was already feeling heavy pressure to change its immigration policy, and that's now increasing.
"The events in Cologne have profoundly changed the dynamics of Berlin politics," a group of Der Speigel writers say. "Chancellor Merkel and her confidants fear that it will only get more difficult to enforce their current refugee policy."
Her party, the Christian Democrats, is already taking a tougher line on immigrant crime: In an announcement this Saturday called the Mainz Declaration, the party called for stripping asylum status from anyone convicted of a single crime, as well as making it easier to deport immigrants convicted of crimes.
"The events of New Year’s Eve have dramatically exposed the challenge we’re facing, revealing a new facet that we haven’t yet seen," Merkel told reporters on Saturday.
The chancellor has not announced any new restrictions on immigrant flows into the country. But the Mainz Declaration does call "for a clear reduction in the number of migrants entering the country," Deutsche Welle reports.
Ominously, we're already starting to hear about attacks on foreign nationals by Germans, seemingly out of anger at the New Year's Eve assaults. On Sunday, a Syrian man and a group of Pakistanis were separately assaulted by mobs in Cologne.
And Germany's anti-immigrant fringe is using the attack as a rallying point. On Saturday, 1,700 people joined a PEGIDA rally in Cologne protesting Merkel's immigration movement. In an ironic echo of the attacks themselves, the ralliers pelted police with beer bottles and firecrackers. The police employed tear gas and water cannons to break up the rally.
Improbably, it looks like things in Cologne are just getting worse.
The attacks tapped into Germans' deepest fears about migrants
It took about five days for the New Year's Eve assaults to become national news in Germany. Once it did, the public outcry was understandably furious.
The outcry, however, wasn't primarily focused on policing failures, but rather immigration policy: The alleged North African or Arab identity of the perpetrators has a lot of Germans questioning their country's relatively welcoming stance toward migrants and asylum seekers. The events in Cologne, it seems, have tapped into Germans' deepest anxieties about immigration, specifically the recent wave of migrants and refugees from countries such as Syria, Iraq, and Afghanistan.
Chancellor Angela Merkel has adopted one of Europe's most open policies for refugees; Germany admitted about 1.1 million asylum seekers (in addition to non-refugee migrants) in 2015. Many of these refugees hail from Syria and other Arab countries, or from Afghanistan, all of which is fairly new for Germany: In prior years, German migrants tended to come from other European countries or Turkey.
This wave of immigration has stoked German anxieties. In September, Eurostat polled people around Europe as to what the top issue facing the continent was; Germans answered "immigration" at higher rates than people in any other European country (a big change from the 2012 edition of the poll):
The Cologne attacks also play into German fears about immigration and crime. The research on this question is mixed. In the United States, studies strongly suggest that immigrants are no more likely to commit crimes than native-born Americans; the research on European countries tentatively suggests that immigrants are modestly more likely to be convicted of crimes than native-born Europeans (the reasons for this are hotly contested).
Regardless of the truth of the situation, the perception that more immigration could lead to more crime in Germany is very real. This comes, at least in part, from a wave of thefts in Cologne that have been linked to immigrants. Der Speigel explains:
The search for the perpetrators initially led the Cologne investigators to a criminal milieu, one that has plagued Cologne for years, especially in nightlife districts or around the train station. It's typically groups of young pickpockets who use perfidious tricks to snatch wallets, phones and other valuables off unsuspecting pedestrians. The perpetrators dance up to their victims in a pretend celebratory mood, rub up against them and rob them. Those who try to defend themselves are insulted, threatened or even hurt.
In Cologne alone, more than 11,000 people have been robbed in this way in the last three years. According to police, all of the perpetrators have been male and in the majority of cases, they have come from North African countries such as Morocco and Algeria. The authorities are also investigating groups of men from central Africa and Kosovo.
The Cologne attacks have supercharged this fear, shifting Germany's immigration debate in ways that could have profound implications for the country and beyond it.