Seeking new inspiration and a fresh start, married musicians Daphne (Rosy McEwen) and Darcy (Dev Patel) move to the Welsh countryside to finish their new record. While collecting audio samples, Darcy inadvertently creates a field recording of mysterious sound never before heard by human ears. The discovery renews Daphne’s creative energy, but as the echoes of her music bleed into the surrounding landscape, ancient and malevolent woodland forces are disturbed. One day, a stranger arrives on their doorstep. The couple initially embraces the stranger, who helps them navigate and understand their new environment, but Darcy grows suspicious of his obsession. As jealousy and paranoia infect the makeshift family, the line between reality and myth begins to blur.