The mysterious man looks completely wrong to me. In the text of conspiracy thriller 'Embassy,' an online novel by Richard Doetsch, the character is described as 'a starkly thin fellow with a protruding Adam's apple.' My brain goes: (ital) Alan Rickman! (end ital) But when I click on the chapter's accompanying video, the man is younger, tanner, scruffier. He's dressed like he should be bumming clove cigarettes at a concert, not spying on the Greek Embassy. What I'm reading is a Vook -- a video/book hybrid produced in part by Simon & Schuster's Atria Books. Interspersed throughout the text are videos and links that supplement the narrative. In one chapter, the Greek ambassador receives a mysterious DVD, and readers must click on an embedded video to learn what's on it. In another, kidnapper Jack ominously tells his hostage that he's going to prove that he means business. 'How are you going to do that?' Kate asks. 'Are you squeamish?' Jack replies. Below that dialogue, a little box encourages readers to 'SEE WHAT HAPPENED NEXT' by clicking the play button. Vooks represent just a few examples of a new genre that has been dubbed v-books, digi-books, multimedia books and Cydecks, all with essentially the same concept: It's a book ... but wait, there's more! The first six books of text/Web hybrid 'The 39 Clues' have nearly 5 million copies in print, and nearly 700,000 registered users for the site. 'The Amanda Project,' released this fall, is set to be an eight-book series. Brad Inman, founder of Vook, said his company will release as many as 200 online-only titles next year. 'It's very inexpensive in scale. We're talking thousands of dollars, not even tens of thousands of dollars,' for each project. Is a hybrid book our future? 'As discourse moves from printed pages to network screens, the dominant mode will be things that are multi-modal and multilayered,' says Bob Stein, founder of the Institute for the Future of the Book. 'The age of pure linear content is going to pass with the rise of digital network content.' Predicting the eventual death of the traditional novel sounds practically heretical. But the genre has actually existed in English for only about 300 years, and that experimentation and evolution have always been a part of the way we tell stories. Perhaps the folly isn't in speculating that the book might change, but in assuming that it won't. -- -- -- The bells and whistles in hybrid books are endless. In 'The Sherlock Holmes Experience' -- one of six books, including 'Embassy,' published by Vook since the company launched in October -- two classic Arthur Conan Doyle stories are annotated with video clips of historians sharing Holmesian trivia. Hyperlinks send readers to Wikipedia pages explaining old-fashioned terms. In 'The Amanda Project,' a young-adult series launched this fall, three teens investigate a friend's disappearance, primarily in a book but also on a companion Web site where readers are encouraged to upload their own 'clues.' Some contributions will be incorporated into the second book, due in February. In 'Skeleton Creek,' the narrative alternates between the written diary of Ryan, a housebound teen investigating strange occurrences in his home town, and the video missives of his best friend, Sarah. Ryan, and the reader, access Sarah's transmissions by logging onto a Web site with passwords provided in each chapter. Myebook. which helps users self-publish books online, allows text to be mashed up with video and applications. These hybrid books 'truly (are) groundbreaking, and I don't use that word lightly,' says David Levithan, a Scholastic editor who worked on 'Skeleton Creek' and 'The 39 Clues,' a series involving an elaborate online game. 'It's expanding the notion of what storytelling can be.' Hybrid books feel like instant gratification and guided, packaged experiences. What they don't feel like, at least in certain examples, is reading. Picture losing yourself in the fictional world for hours on end -- the way the characters sound in your mind, the way unfamiliar references give you pause. (ital) What (end ital) is (ital) a nosegay, anyway ?(end ital) If you could see the authoritative version of a character right away, without waiting for the movie version, would you? If a floral dictionary were just a click away, would you interrupt your reading to visit it? Would these abilities represent the sort of enhanced involvement that book lovers have always dreamed of? Or would they tamper with our imaginations? Many current hybrid books are aimed at kids, the first generation of 'digital natives.' 'What they really love is staying in that world,' says Lisa Holton of Fourth Story Media, which packaged 'The Amanda Project.' 'We as adults can't even begin to understand their relationships with technology.' But what happens to the traditional reading experience involving a fat novel, a fireplace and a cup of tea? 'It's very common for (a teen) to read, but have her phone there and her computer there,' says Patrick Carman, who wrote 'Skeleton Creek.' 'For her, having this multimedia experience (ital) is (end ital) like sitting down with a cup of tea.' Carman's niece is a generationally aware 14-year-old, Madison Wilcox. 'The books with the videos, I think they keep our interest better,' Madison says. 'The generation we're in is always using technology. (Hybrid books) are easy to blend in with our lifestyles.' 'We don't pretend that it's a book because it's not,' Inman says. With the Vook, 'there's an expectation that you're not gulping the text.' Instead 'you're tasting the text,' dipping in and out at will. One wonders how this affects the way we read, perhaps shortening our attention span. 'When you go from one task to another, your brain does slow down,' says Earl Miller, a professor of neuroscience at MIT. 'Your brain has to reconfigure its cognitive network. For the first few seconds (of the new activity) there's an increase in errors' in our comprehension. 'The way the brain handles language is very different than the way it handles pictures,' says Clifford Nass, a Stanford professor who studies multitasking. 'One of the ways is pacing. You read a book and you stop whenever you'd like. When you watch a video, you can't do that. It goes on.' It's active entertainment vs. passive. Retention and comprehension are moot when the narrative in question is, for example, 'Embassy.' Missing a paragraph or two won't affect a reader's understanding of the plot. In reading 'Embassy,' what concerned me wasn't that my brain was getting overworked but that my imagination wasn't. The pleasure of reading has always been its uniquely transporting experience: the way a literary world might look completely different to two readers. But when the 'true' representation -- like clove cigarette guy -- is immediately provided to the reader, imaginary worlds could be squelched before they can be born. David Sousa is a consultant in educational neuroscience and author of 'How the Brain Learns to Read.' In his classroom research, he says, 'we find that kids are not able to do imagining and imaging as exercises' as well as they once did, 'because video's doing the work for them. ... They still have the mental apparatus for that; the problem is they're not getting the exercise.' Reading has traditionally been one of imagination's personal trainers. Skipping from medium to medium might provide other benefits but may adversely affect the way we create our own worlds. Some hybrid books' companion activities seem designed to exercise creativity. Madison, the 14-year-old, says that she's never been a bookworm, and the multimedia aspects of her uncle's books have made her more willing to read other things. Stein, of the Institute for the Future of the Book, says that whatever assumptions we make now about hybrid books likely won't hold true when the medium grows up. 'Things like the Vook are trivial. We're going to see an explosion of experimentation before we see a dominant new format. We're at the very beginning stages' of figuring out what narrative might look like in the future. 'The very, very beginning.' 