which is a really wonderful film. tilda swinton, who i think is great in almost everything, is a botanist, a flower trader. she is in bogota, where her sister is in hospital. we see her visiting her sister and talking to her sister and her partner. she is woken in the middle of the night by a sound. a strange booming sound. and she thinks that there must be building work going on next door, but she speaks to people and there isn't any building work going on. and she starts hearing the sound wherever she is and it's a really peculiar sound, and she becomes obsessed with the idea that nobody else appears to be able to hear it. so she goes to a sound engineer to say can you make a copy of this sound for me to describe it? here is a clip.