In the exhibition room of Berlin's old Tempelhof Airport, three burned-out cars lie on their sides. The windows, interiors and paintwork are gone; all that remains are lumps of twisted and rusted metal. Next to them is a rough circle of tents and scattered mats. A picnic chair has toppled over on one, others are strewn with abandoned bags, camping equipment and discarded fairy lights. "Everything you see here is original from the festival on October 7th," Ofir Amir explains. He's referring to the Nova Music Festival, where around 400 people were murdered on 7 October 2023. In the week...