Kate Dickie is on terrific form here in this tensely crafted short feature. She is ''Lorna'', an emergency co-ordinator for the fire service who responds to a 999 call from the panic-stricken ''Gemma''. Her home is on fire and her young son is trapped upstairs, and so having despatched the fire brigade, ''Lorna'' attempts to keep her caller calm and safe until assistance arrives. Of course, the mother isn't about to stay safely at the bottom of the stairs whilst her child is at risk, and so as the situation becomes even more perilous the lifeline of this telephone conversation becomes even…