T his film from the London-based artist Aura Satz is an exploration of sirens – as in the warning devices, not the mythical creatures that lure unsuspecting men to their doom. Really it’s an art film, and might have been more at home in a gallery where audiences would be able to engage with its striking images and experimental soundtrack for as long as the mood takes them. As a feature-film experience it becomes an endurance test, a battle to pay attention and concentrate for the whole thing. It opens with a drone shot of a huge siren in the middle of what looks like a residential neighbourhood, ready to alert residents to heaven knows what threat. Over the top, a shrill, insinuating track from composer Laurie Spiegel buzzes with the nagging whine of an electronic mosquito. There are some interesting ideas here.…