Twilight thesp Jackson Rathbone and Erika Christensen are set to topline Paul Williams’ “The Idiot,” which Intandem Films is shopping to buyers in Cannes.

Pic, a thriller based on the book by Fyodor Dostoyevsky, is skedded to begin lensing in L.A. in September. Donald Kushner (“Tron”) produces.

Story follows a man of pure spirit who thinks he can save the world but is caught between a wildly beautiful and fragile woman, a woman he is falling in love with and a friend who is trying to destroy him.

Intandem is also shopping Helen Hunt’s second directorial effort, “Ride,” in which a strong-willed mother follows her 20-year-old son to L.A. after he quits college to become a surfer. Each ends up finding their own version of love in unlikely places.

Hunt also stars in the $6 million romantic comedy and penned the script.

Intandem reps “Ride” internationally while CAA will rep the film domestically.