My initial concern was that the crowd was dense enough that I would have difficulty taking pictures. I need not have worried. As the devils lit their first fireworks, and a rain of sparks began to scythe through the crowd, everyone in front of me disappeared, leaving me with an unobstructed view of the proceedings.
A correfoc (literally, "fire run") is another of those quirky Catalan traditions, a cross between a pagan festival and a ground-level fireworks display. Teams of performers dressed as devils and witches – collas de diables – march through the streets, accompanied by home-made monsters in the shape of dragons, insects, elephants and other animals, real or fantastic. Both the monsters and the pitchforks carried by the devils are fitted with anchor points for fireworks. At a signal from the leader of the colla, the fireworks are lit, and total chaos breaks out: sparks fly everywhere, spectators and fireworks both scream, the devils dance, and the monster is whirled rapidly around, spewing fire all around it.
Taking pictures during a correfoc is an interesting challenge. Most people in the crowd are more than happy to let you get as close as you want to whatever fire-spitting monstrosity is currently blasting flames across the street, so getting a clear view is not necessarily a problem. But things move fast, and light levels change rapidly, so composition and exposure are both tricky. Then there's the fear factor. The devils wear safety glasses and thick capes and hoods to protect themselves against flying sparks. If you have some kind of eye protection, you'll probably be fine: when the sparks land on bare skin, they sting briefly, but mostly don't leave lasting burns. But there's something intimidating about staring into a river of white sparks from a distance of a couple of meters away, and it's hard to keep your mind on the technicalities while being deafened by the shriek and bang of fireworks going off in your face. Even if you know it's harmless, it feels like being in the middle of a war zone. Quite a few times, I found myself instinctively shrinking back.
The modern correfoc evolved from a much older tradition, the ball de diables, which is mentioned in records as far back as the 12th century. Modern fireworks have made the spectacle more kinetic – earlier versions probably used fire in the form of flaming torches, but actual pyrotechnics may have been a late addition. Still, the medieval version may have had much of the same feeling of Walpurgisnacht mayhem as its modern counterpart, and probably delighted and terrified spectators in much the same way.