The Project Runway season 12 finale airs Thursday and one designer will be named the winner after showing their collection at New York Fashion Week.

Getting to the final runway show was a grueling process for the contestants and one in particular had to deal with a designer's worst nightmare: a stain on a garmet right before it hits the runway.

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A preview video for the final episode of the season shows all the designers -- Alexandria von Bromssen of California, Bradon McDonald of California, Justin LeBlanc of North Carolina and Dom Streater of Pennsylvania -- backstage at New York Fashion Week. The clip shows them working on their collection for the last few minutes before it goes on the runway for the world to see.

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Bradon McDonald gets quite nervous when his models bring their coffee and food close to his clothes -- and rightfully so. He then discovers that one of them spilled coffee on the dress she is supposed to wear down the runway. He is almost reduced to tears and is seen dabbing the stain with a tissue hoping to get it out before the dress goes out on the catwalk. The show's mentor, Tim Gunn, tries to console him but to no avail.

Viewers will have to wait and see how he deals with the situation on Thursday at 9/8 p.m. Central on Lifetime.

Joining host/judge Heidi Klum and the rest of the panel this week is Scandal actress Kerry Washington. Wearing a floral cocktail dress from Stella McCartney's Resort 2014 collection, she was a guest judge and shined next to Klum, who wore a floor-length gold gown.