Director Deniz Gamze Ergüven has made not only one of the best films of the past year but also one of its most important, and in the same blow managed to establish herself as one of the most promising new voices in cinema of recent years.

Five sisters splash and play in the ocean on the way back from their last day of school, embracing summer and having fun with local boys. A neighbor witnesses this and tells the girls’ grandmother they’ve been caught in the act of obscene behavior – the catalyst for their freedom being increasingly taken away. Phones and computers go first; curfews are implemented; and they receive daily lessons on housekeeping. Then the bars on the windows go up and the girls are married off one by one, all part of keeping the family legacy clean and pure. The sisters, led by the youngest, plucky Lale (Günes Sensoy), must find a way to retrieve the rights stolen from them.

The actresses playing the five sisters are all wonderful and naturalistic, imbuing their characters with distinct voices despite many of them having little acting experience, and Sensoy is a revelation. They operate as a small unit – a notion reinforced by the frames where the girls are a mass of limbs, toppling over one another, tugging at hair and pushing each other out of the way. They are, crucially to the film, believable as sisters, with the sort of comfort in one another’s presence that seems untouched by forced chemistry or obvious acting choices. Their warmth pours onto the screen, making it impossible not to care about the characters and their happiness.

The film is also beautifully composed. Ergüven and cinematographers David Chizallet and Ersin Gok find pitch-perfect notes in capturing the sisters’ unbreakable will and the severity of their situation, most importantly capturing how all of this would appear in the eyes of a character as young as Lale. Rather than overindulging in theatrics about their home imprisonment, the film instead shoots it with a sturdy frankness. Lale is increasingly cunning and calculating with each new development, and the camerawork evolves alongside her. It’s when the sisters break through barriers, as well as in scenes such as the first walk home from school, that the camera captures pure artistry. Sure, a big scene at a local sports event never really goes past surrealist blurs due to what must have been budgetary restraints (or Ergüven’s inexperience), but as a whole the film’s scenery feels lived in and we are with the girls as they make their every move. We feel what they feel, from fear to relief to joy and pain.

Warren Ellis’ score makes sure each string is plucked in accordance with what the audience feels. Used softly it’s fine – but when it soars it becomes integral, causing the heart to leap into the throat in pure anticipation.

But really, for everything the film nails (and it’s quite a lot) the main joy of “Mustang” is how emotionally evocative it is. Named “Mustang” because the girls’ spirits never break, the film lingers with you long after its running time of just over 90 minutes – just enough to tell the story to its fullest and leave you speechless (or, if you’re like me, in tears). Lale is the hero of her own story here, and it’s immense powerful to see the amount of agency given to all the sisters, who fight with humor and courage against the idea that a society can dictate what they do with their bodies and minds.