Our friends told us that in Sant Llorenc the weather changes towards the end of August. Endless days of thick summer heat gives way to something altogether more dramatic. Ominous black clouds the size of cities. Rain drops like translucent grapes. Fork lightening like you see at the cinema. Thunder, that carves open the sky, like unimaginably huge boulders crashing downwards from the high mountain peaks.

We followed the river Muga out of Sant Llorenc, into the valley beyond. Our aim was to reach a reservoir which we thought may be a good place to leave the Lento box to make an overnight recording. Eventually, along rough tracks surrounded by dense trees and noisy cicadas, we reached the water. Our way however was blocked. Two white horses.

Impressive creatures. Standing astride the track. They had their backs towards us. We stopped, and watched, and kept our distance. Despite facing the other way the horses knew we were there. In low voices we shared ideas on what to do, whilst continuing to watch. Both stood firm. They were expressing only the smallest of movements through their tails.

Some time passed. It felt like they were communicating something to us. But what? The valley with all its assorted cicadas seemed, somehow, to have fallen silent. We decided not to try to pass them. Something perhaps in the way they moved their tails said turn back. So we turned back.

Returning along the track we entered an area of the valley where the shallow river sounded unusually sonorous. The way the water tumbled over the rocks. the depth, and the particular arrangement of the trees. Just off the track a tree looked down into the gorge, so we tied the lento box to it. It was the perfect place for it to record. Perhaps, if we could have read the tails of the horses, this was what they were trying to say. Record back where you've come. Where it's sheltered. And where the river wrills. There's a storm. Coming.