Invoking Yell has its international première at Panic Fest 2023 One of the disparate story strands in Patricio Valladares’ Covid-curtailed, inchoate sci-fi Embryo (2020) involved a music video shoot gone awry in the Chilean backwoods – and with Invoking Yell, Valladares, working with his regular co-writer Barry Keating, revives this basic premise, while confounding the viewer’s sense of genre. This ambiguity of genre is…