Level 5 has registered a trademark for Professor Layton and the Unwound Future.
Found by Siliconera, the game would be the final chapter in the latest Layton trilogy, which is a set of prequels set three years before The Curious Village, back when Luke first became Layton's apprentice.
The title will follow The Devil's Flute, and The Mask of Miracles, which is set for release this fall in Japan, and it's being suggested that the plot revolves around Layton and Luke heading into the future.
The third Layton game from the first trilogy, The Last Time Travel, has yet to make it outside of Japan.
We really wish it would hurry.