The mastermind behind "Hereditary" is here to scare the living daylights out of you.

Writer and director Ari Aster already stunned us with his evil genius with last year's horror hit. Now he's back with "Midsommar," and while the trailer looks like sunshine and flowers, something dark and terrifying is lurking beneath.

Described as a "Scandinavian folk horror" tale, the movie follows a couple (Florence Pugh, Jack Raynor) visiting a summer festival in rural Sweden. But what begins as an idyllic retreat quickly devolves into a violent and bizarre competition at the hands of a pagan cult.

The trailer's initial dreamy, sunlit, colorful vibe provides a stark contrast to the disturbing imagery seen later, like a bear with its guts hanging out.

"Midsommar" opens August 9.