Despite being involved in the development of enough upcoming projects to make your head spin, Guillermo del Toro has struggled recently to actually begin principal photography on any single film. Some nine months ago he passed on directing The Hobbit due to its now-infamous production delays, and just last Friday del Toro's At the Mountains of Madness adaptation became officially dead in the water.

Now the Pan's Labyrinth creator has opened about just what happened with At the Mountains of Madness, saying that he will actually be behind the camera again this fall, on Pacific Rim.

With the assistance of James Cameron, del Toro was poised to transform author H.P. Lovecraft's At the Mountains of Madness into a 3D, $150 million motion picture with Tom Cruise in the lead. It had the makings of a dream project come true for fans of Lovecraftian Horror, but was always considered a risky proposition - in part due to the limited appeal of the source material.

Deadline sat down for a Q&A session with del Toro, in which the filmmaker admitted that he doesn't know exactly why his Mountains of Madness collapsed so suddenly:

"I haven’t had a face to face with [Universal chairman Adam Fogelson and co-chair Donna Langley] . We’ve exchanged a few phone calls. In my mind, we were given the parameters of a budget and screenplay, and I was given the chance by the studio to create a visual presentation. They were blown away by the visual presentation, they openly admitted to loving the screenplay, saying it was dead on. And we hit the target on the budget they gave us, not a figure I arrived at.

"This came after months and months of storyboarding, haggling with VFX companies, and bringing down the budget number. The week before the decision, I was scouting in the border of Canada and Alaska. We were a week away from opening offices in Toronto. We were crewed up, and frankly, I am as puzzled as most people are."

Don't Be Afraid of the Dark movie Gullermo del Toro Katie Holmes

The del Toro-produced remake of Don't Be Afraid of the Dark will finally arrive in theaters this August, and he (del Toro) describes that as being the sort of R-Rated "very intense movie [made] in a very classical mold" that he was aiming for with Mountains of Madness.

An R-Rating for the Lovecraft adaptation was very much a deal-breaker for him too, according to del Toro. He seems aware that this may have contributed to the project's termination, but points out that he'd made his feelings on the matter quite clear to studio heads:

"Ultimately, I think the MPAA could rule the movie PG-13 because the movie and the book are not gory. If that is the outcome, fine... The only thing I know about 'Mountains' is, I do not want it to be bloody, I do not want it to be crass, but I want it to be as intense as possible.  And those discussions were had in the open. Everyone knew this was my position, that I knew I was asking the chance for the movie to be what it needs to be. I don’t think it’s a good idea to relinquish that on paper."

Fans of the darkly imaginative auteur can at least take comfort in the news that his next directorial effort, Pacific Rim, is "unequivocally" set to begin principal photography this September, with Legendary Pictures eying a Summer 2013 release date.

While del Toro's lips were by and large sealed about the picture - which is officially described as being a futuristic sci-fi thriller in which Earth must defend itself against attacking creatures - he did offer the following tidbit:

"People got it confused with the 'Godzilla' movie a few months ago but we cleared that up. I can say the scope and imagination that have been outlined in it are absolutely appealing to me. I cannot say more, it’s not the time."

So Pacific Rim will be a monster invasion movie of sorts, with del Toro calling the shots? That should help to tide over fans who are hoping to see At the Mountains of Madness make the leap to the big screen sometime in the next few years.

Source: Deadline