Desperate to save their crumbling marriage, Will and Alice Harding retreat to an isolated cottage in the English countryside. A landscape of standing stones and holy wells provides perfect fodder for the fertile imagination of their seven-year-old son, Toby. Toby vanishes before his father's astonished eyes only to reappear, with an impossible explanation for his disappearance. Soon, Alice notices that her son is different, changing into a monstrous stranger. Her fears are compounded when a hooded figure is seen skulking around their troubled new home. Over the days that follow, Alice fears for her own sanity, as local tales of dark magic and sacrifice appear to be true. Will suspects that his wife is mentally collapsing as a result of his past infidelity. With their marriage stretched to breaking point, the Hardings stand to lose more than just each other, as Toby deteriorates further with every passing hour, feeding the vengeful spirit of... The Other Boy