On a farm in rural Iceland, Pétur (Björn Hlynur Haraldsson) is visiting his brother, Ingvar (Hilmir Snær Guðnason). Expecting lunch with Ingvar and his wife, Maria (Noomi Rapace), he’s perplexed by a third guest at the table. “What the fuck is this?” he asks. Audiences might well ask the same throughout Icelandic film-maker Valdimar Jóhannsson’s fun, freaky debut feature.

In the first act, hot hipster couple Ingvar and Maria deliver a lamb. A cut to their awestruck faces tells us that this creature is … different. They name her Ada and declare her a blessing. Jóhannsson’s film is not quite a horror, though it flirts with the genre’s motifs. There is the constant sense of danger lurking in the frostbitten depths of the nearby lake, or just behind the postcard-perfect mountain that looms over their home. Maria has creepy dreams of curly-horned rams with sinister, glowing eyes; the ewe that gave birth to Ada waits stubbornly outside her bedroom window. Inside, Maria swaddles the lamb in a blanket, cooing and singing her to sleep. In one adorable scene the pair bathe together. When Ada disappears, she becomes feral with fear and maternal rage.

A yellow cable-knit cardigan becomes a harrowing talisman, not unlike the red raincoat in Nicolas Roeg’s Don’t Look Now. Jóhannsson teases the possibility of a monster, but waits to reveal his hand. When he does, there’s more than a touch of gallows humour. I laughed out loud at his audacity, and had nightmares later.