Far more dark fantasy than horror, the Icelandic slow-burn thriller Lamb nevertheless serves as a master class in suspenseful wonder.

The tale of melancholic yet seemingly content agrarian couple Maria (Noomi Rapace, Prometheus) and Ingvar (Hilmir Snær Guðnason, A White, White Day) gets off to an eerie, spectral start, then settles in to a fairly straightforward story of a simple, isolated existence.

That is until one of their ewes births a sheep/human hybrid, whose gradual reveal of its full appearance, doled out in obscured and distance shots by co-writer/director Valdimar Jóhannsson, builds significant allure.

Naming the creature after their deceased daughter Ava and raising it as if she was wholly human, the couple — and Jóhannsson — play this odd scenario largely straight, resulting in a surprisingly sweet family drama.

Still, an undercurrent of tension runs through it all, from Ava’s jealous ovine mother’s attempts to reunite her with the flock to the arrival of Ingvar’s immature brother Pétur (Björn Hlynur Haraldsson, Jar City), whose troubled past and disgust at this, er, blended family makes him an intriguing wild card.

A special effects technician with such major credits as Rogue One and Flags of Our Fathers on his resumé, Jóhannsson proves a natural behind the camera in his feature directorial debut. Anticipation reigns supreme and payoffs are few, but the filmmaker rewards viewer patience with multiple jarring moments and creative imagery, firmly establishing him as a talent to watch.

Grade: B-plus. Rated R. Now playing at Carolina Cinemark and the Fine Arts Theatre

(Photo: A24)