Harry Potter actress Emma Watson has bared it all to help save the world.
The steamy photos will be featured in photographer James Houston's upcoming book, Natural Beauty, to raise money and awareness for environmental issues.
"My friend is supporting GlobalGreenUSA with his book Natural Beauty. It's out now. : ) X," the 22-year-old actress tweeted.
"My latest project, Natural Beauty, is a photographic series inspired by the connection I feel to nature in my design work and in the environment," Houston explained on his blog.
"I shot some of the world's leading celebrities and top models who are also environmentally conscious."
In addition to Emma Watson, Adrian Grenier, Christy Turlington, and Elle Macpherson all posed for the 120-page-book.
Houston has documented his journey in twelve part webisode series which he will launch at the end of March.
Watch the trailer here: