In this season's casting special, "Road to the Runway," sixteen new designers will be introduced with a behind-the-scenes look from their casting auditions; home visits, casting submissions, and sit down interviews. Tim Gunn will present the designers in carefully carved out categories that will lead you into the season premiere.

Kicking off the season with an Unconventional Materials Challenge, Heidi and Tim welcome the designers at a Season 15 launch party.  The designers are shocked to learn that the decor for the party will also serve as their materials for their looks. Savannah Guthrie joins the judging panel.

The designers must create an outfit to flatter all body types, and the challenge proves to be more difficult for some than others. Guest judge Nina Dobrev joins.

The designers have to create a look that sparkles not only in daylight, but also under blacklights on the Runway. Anxieties rise when the unusual materials leave many of the designers in the dark. Jamie King joins the judges this week.

In the Heidi Klum Swimwear Challenge, the designers create their own fabric to use in crafting a stylish swimsuit. The winner will have their design sold as part of Heidi's swimwear line! But the contestants lack of swimsuit experience makes for a harder challenge than expected.

In the season's first Team Challenge, the designers exercise their business savvy when they pitch their collection ideas to raise money from a group of mystery investors. The stakes are raised when they learn that the winning team members will each receive $5,000, and the winner will be featured in Marie Claire magazine!

The designers are excited to attend a press event, but their festive mood is quickly spoiled when the party turns out to be a challenge. The misdirect proves to be more than most of the designers can handle, as many of them have to start their looks over completely when criticized by a disappointed Tim Gunn. Emily Ratajkowski joins the judging panel.

The exhausted designers are whisked away to Universal Studios Orlando to recharge their batteries with a roller coaster or two. They are then challenged to find inspiration from their experience at the theme park to design a look for the "Urban Jungle." Guest judge Rebecca Minkoff joins.

The designers are faced with their second Team Challenge of the season and must work together to create 3-piece collections to be shown in a SoHo pop-up shop. However, working in teams leads to tensions and tantrums as the designers struggle to have their voices heard. Guest judge Kelly Osbourne returns.

The designers are surprised when each one of them gets a special guest from home. But the emotional reunions with their mothers, daughters, and friends are quickly overshadowed by the drama of the next challenge when the designers learn that their newly arrived loved ones will also be their clients-and there is $50,000 on the line! Olivia Culpo and Katia Beauchamp join the judging panel.

The designers take a majestic helicopter ride high above NYC for inspiration for their next challenge: to create an editorial, high fashion look for Marie Claire magazine. Guest judges Anne Fulenwider and Camilla Belle join the panel.

The designers are challenged to draw inspiration from metal and machinery for their next look. However, in another Project Runway first, they must create their avant-garde design using the metallic unconventional materials, as well as conventional materials from Mood. Shiri Appleby joins the judging panel.

In the final challenge before Fashion Week, the designers take a surprise trip to Austin, Texas, where the city's unofficial slogan is "Keep Austin Weird!" Once there, the designers are faced with an Unconventional Materials Challenge, leading them to create amazing (and weird!) pieces with the knowledge that the losing designer will be sent home just one step away from Fashion Week.

After heading home to work on their Fashion Week collections, the designers are visited by Tim, who is not impressed with everything they have created so far. The designers return to NYC and present the judges with three pieces from their collection, and all of them realize how much work they have left before presenting all of their pieces at Fashion Week. Michael Kors returns as a guest judge.

Fashion Week is finally here, and the designers rush to put the final touches on their collections. Four designers will have their dream of showing at New York Fashion Week, but only one designer will reach the ultimate goal of being crowned the next Project Runway winner! Guest judge Zendaya joins the panel.

The Season 15 designers reunite with mentor Tim Gunn to discuss their Project Runway experience. They come ready to reminisce, share emotions, and settle scores.