Dad (Hassan Madjooni) sits moodily in the back with an ostensibly broken leg, while Mom (Pantea Panahiha) drives and tries to laugh when she’s not holding back tears. An energetic youngster (Rayan Sarlak, in a star-making performance) keeps exploding into song and scrambling around the car. All are fussing over their sick dog and getting on each others’ nerves; only the mysterious older brother (Amin Simiar) is quiet. It’s clear they’re on a road trip across a rugged, often…