As the anniversary of the Christchurch mosque shootings nears, the world has had a reminder of the ominous threat of extremist violence.
At Hanau in Germany, nine people of immigrant heritage were murdered in the third major far-right attack in the country in recent months. A pro-migrant politician was shot dead last June, and a synagogue in Halle was attacked in October.
After the latest attack, thousands of people attended vigils across Germany. A gunman with apparent far-right beliefs had targeted a shisha (hookah) bar and café. Among the dead were Turkish citizens.
Chief federal prosecutor Peter Frank said a manifesto showed the suspect, Tobias Rathjen, 43, had a "deeply racist worldview". A federal terrorism investigation has been opened. Rathjen, who was legally able to have firearms, was found dead at his home after the rampage.
Counter-terrorism expert Peter Neumann, of King's College, London, said the manifesto contained "mostly extreme-right views, with a do-it-yourself ideology cobbled together out of parts found on the internet".
Germany's Interior Minister Horst Seehofer said the danger from far-right extremism, anti-Semitism and racism was "very high" and the "biggest security threat facing Germany". Police are being deployed to mosques, transport hubs and other sites to deter copycat attacks after Hanau.
Seehofer spoke of an attack against migrants in 2016 in Munich and seven years of killings by an anti-foreigner group called the National Socialist Underground. "Since the NSU and the rampage in Munich through today, an extreme-right trail of blood has run through our country."
German intelligence agencies estimate there are several thousand far-right extremists in the country. Islamic terrorists have killed 17 people in Germany since 2011, most in one attack in 2016.
In Germany, far-right ideas have a mainstream outlet through the Alternative for Germany (AfD) party which has between 10 and 15 per cent support in polls, has 89 seats in the Lower House and regional MPs.
Politicians have accused the AfD of normalising hate speech and promoting anti-immigrant views.
This month, German police arrested 12 extremists allegedly plotting attacks on mosques, similar to the Christchurch shootings.
Racism, anti-immigrant sentiment and xenophobia are easy to stir. Fears over the coronavirus outbreak have reportedly resulted in discrimination against Asian people.
Speaking at a recent ceremony to commemorate the victims of the Nazis, German President Frank-Walter Steinmeier said that hatred and abuse are spreading. Problems of the past were "raising their ugly heads again in a new guise" 75 years later.
Kiwi director Taika Waititi's Academy Award-winning film Jojo Rabbit, about Nazism at the end of World War II, has interesting points to make about extremism and living through difficult times - as relevant today as when the movie was set.
Jojo Rabbit features the words of Austrian poet Rainer Maria Rilke: "Let everything happen to you: beauty and terror. Just keep going. No feeling is final."
Even in a situation of horror, hatred and chaos, moments of joy and hope can still escape and bloom. And the natural transition of time will turn something that was once grimly all-powerful into history.
Extremist violence, whether in Germany or Christchurch, are ultimately futile acts, even though they cause great suffering.