It is 10:30am on April 22; a sunny Wednesday morning.

Anwar al-Bunni, a 61-year-old with small dark eyes beneath bushy brows, is standing outside Berlin Hauptbahnhof, the German city's main train station, in a light grey jacket and dark pants. Where travellers and commuters usually hurry in and out of the large glass and steel building, all is quiet today. Whoever can, is staying at home because of the coronavirus.

Al-Bunni calmly picks a cigarette from a silver case and lights it. There is still enough time for a smoke before the train that will take him 600km (373 miles) to the western German city of Koblenz is due to depart.

The renowned Syrian human rights lawyer is making his way to Koblenz's Higher Regional Court, where he will testify in a case due to begin the next day. But al-Bunni is more than just a witness at the trial. He is, many of those connected to the trial agree, one of the people who made it possible.