Gosling, who featured in "The Notebook", penned the script for sci-fi thriller "How to Catch a Monster", and he has cast Mendes as Cat, the head of the Big Bad Wolf Club in the film, according to movie news site Bloody-Disgusting.com, reports dailystar.co.uk.
His "Drive" co-star Christina Hendricks will portray lead character Billy, a single mother of two who gets sucked into a fantasy underworld.
The production work on the movie is scheduled to start in May. The Hollywood couple began dating in 2011 after meeting on the set of upcoming film "The Place Beyond the Pines".
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