In a time when a model casting can single-handedly determine the success of a fashion show, securing a thrilling new face on an exclusive contract is an increasingly vital conduit to that purpose. Prada is great it. As is, judging by the last few seasons under Hedi Slimane's rule, Saint Laurent.

And last night saw the face in which Slimane has anointed with fashion prowess, Grace Hartzel. An 18 year old Indiana native, she signed to Mother Model Management in her hometown three years ago, St Louis and Next Models in New York. It's not difficult to see how her star has been on the ascent since then; combining equal parts conventional sharp cheekboned beauty with a sense of wide-eyed, faintly androgynous otherness, her face explicitly channels the particular beauty narrative of now, of 2014. 

So who is Grace Hartzel? The eldest of four children, she first took to modelling as a means to feel confident about her tall, lean body shape after being discovered dining with her family in a branch of the Cheesecake Factory. Grace told IndyStar.com: 'People are mean... I remember going on spring break my freshman year and there were girls from somewhere in Indiana. They were calling me anorexic. It’s been happening my entire life.'

Though she still has that small-town girl charm and humility about her, right now Grace is on the crux of modelling superstardom. Aside from Slimane and Saint Laurent, she's also captured the attention of Karl Lagerfeld, who cast her in the recent Chanel Métiers d'Art western themed show in Dallas and has walked for Louis Vuitton and Dolce & Gabbana among countless others. On top of that, she stars in this season's edition of Love magazine, in an editorial shot by Patrick Demarchelier. 

But this season, Slimane has kept her all to himself. 

Clearly, Slimane has had his eye on Hartzel for a while. Late last year, for the Saint Laurent Music Project, Slimane cast her in his directorial video for Curtis Harding, the first fledgling artist to be signed to the music collective. It's everything a Saint Laurent music video should be; brooding, moody, black and white and a little frayed around the edges. Sort of like the modern, fashion equivalent of Helena Christensen writhing around on a beach for Chris Isaac's Wicked Game. 

Saint Laurent may have laid claim to Grace Hartzel for now, and in doing so, crystallised her burgeoning career, but we have a feeling other brands will soon want a piece of her too. Watch this space.