EXCLUSIVE: Since he left The Hobbit, Guillermo del Toro’s next film has been a hot topic of conversation. I’m hearing he will next direct At The Mountains Of Madness, an adaptation of the HP Lovecraft tale that will be shot as a 3D film for Universal Pictures. The big surprise is that Avatar director James Cameron will come aboard as a producer. Del Toro was non-committal when I asked him about the prospect of Mountains days ago as we discussed the Comic-Con reaction to Don’t Be Afraid of the Dark. But when del Toro announced at Comic-Con he’d cowrite and produce Haunted Mansion, he told the crowd he’d set his next film shortly, and that it would be scary. At the Mountains of Madness fits that bill, even for del Toro and Universal. The film will be a big ticket item, shot in 3D where Cameron’s expertise can really help. Cameron has said he won’t put his name on many future movies outside of the 3D reboot of Fantastic Voyage at Fox, but I’ve heard he’s making an exception for del Toro. Cameron’s presence helped win over the studio. I’m told the film will begin pre-production in the next few weeks, and shoot next summer.

In the Lovecraft tale, a gruesome discovery made during a scientific expedition to the South Pole in the 1930s hints at the true origin of mankind having come from elder gods from another planet. Bad things happen when those life forms are awakened.

The project is years in the works for del Toro and producers Susan Montford and Don Murphy, and it is easily the most ambitious project contemplated by the Pan’s Labyrinth director. I just put the film high on the list of dream projects for the geek crowd, after it came up numerous times in discussion with geek-savvy film executives, writers and dealmakers.

Mountains was first set up at DeamWorks in 2004 by del Toro and Real Steel producers Montford and Murphy. Del Toro and Matthew Robbins wrote the script, which they are now retooling. The package was acquired by Universal when del Toro made a big overall deal there in 2007, when Universal green lit del Toro’s Hellboy 2 and hoped to establish him as a cornerstone filmmaker. Those plans were put on hold when del Toro surprised the studio and accepted the offer to co-write and direct two installments of JRR Tolkien’s The Hobbit.

Del Toro dropped out of that project earlier this summer, after completing the writing of the two films, and the design of the first installment and half of the second. He cited the uncertainty of a production start due to the paralysis of MGM, which controls the rights along with Warner Bros. Del Toro pledged that he would return to the many plum projects his company is developing at Universal, including films like Frankenstein and the Kurt Vonnegut novel Slaughterhouse-Five. I’m confident that shortly he will be giving Universal one of the most ambitious films on its slate.

Del Toro is repped by WME and manager Gary Ungar.