I know I've seen something atonishing, and I know I'm not ready to review it. "Cloud Atlas," by the Wachowski siblings and Tom Tykwer, is a film of limitless imagination, breathtaking visuals and fearless scope. I have no idea what it's about. It interweaves six principal stories spanning centuries--three for sure, maybe four. It uses the same actors in most of those stories. Assigning multiple roles to actors is described as an inspiration by the filmmakers to help us follow threads through the different stories. But the makeup is so painstaking and effective that much of the time we may not realize we're seeing the same actors. Nor did I sense the threads.