Last month, J.J. Abrams released a very cool, very mysterious teaser called “Stranger” for a new project he was working on. He didn’t say what project it was, so much excitement and speculation ensued. Today, he released the second half of the trailer to EW. This time, he’s being way more forthcoming, and the project is … a truly unique, fascinating book called S. conceived by Abrams and written by Doug Dorst, to be published by Little, Brown on Oct. 29.

I got a brief look at the novel, and it’s a bear to describe, but here goes: S. is basically about the relationship between a grad student named Eric and a college senior named Jennifer. They trade notes in the margins of a (fictional) 1949 novel by a mysterious author named V.M. Straka. S. contains the novel within the novel; copious handwritten notes between Jennifer and Eric (“a conversation that plunges them into the unknown,” according to the book jacket); and dozens of pieces of ephemera between the pages like newspaper clippings and a napkin with a map drawn on it. (S. will come shrink-wrapped so none of this extra material falls out.) It looks like a dense but often funny mystery — and exactly the kind of novel you’d hope for from Abrams. “I could not be more excited for people to get their hands on this book,” Abrams tells EW. “It is difficult to describe because while it is a compelling mystery and love story, it is also much more than that. The work that everyone has done on S. is unlike anything I’ve ever seen. Frankly, I’m amazed it was even possible to do this project at all.”

Here’s the second half of the trailer …

<iframe width="640" height="360" src="http://www.youtube.com/embed/OuZfpt8nxtk?feature=player_embedded" frameborder="0" allowfullscreen></iframe>