Another "Twilight" fan fiction has signed a big book deal.

Hypable.com reported that in midst of the huge success of "Fifty Shades of Grey," written by bestselling author E.L. James, Penguin Books' Berkley imprint has signed a 7-figure book deal with unknown author of two "Twilight" fan-fictions.

"Gabriel's Inferno" and "Gabriel's Rapture" are presently available in e-book format after initially debuting on fan-fiction sites. Paperback editions are due out in the next few months with an initial run of 500,000 copies.

The publisher announced that it would be a "substantial seven-figure deal."

The author behind the books, Sylvian Reynard, is a mystery, the Hollywood Reporter said. The release announcing the deal omitted any biographical information and "Sylvain Reynard" is a pen name.

Berkley will immediately take over publishing the eBooks from Omnific Publushing, a small romance-centered independent publisher.

According to the books' website, "Under Berkley, both titles will receive wider distribution, especially in bookstores around the world. This will provide easier access to current and future readers."

The first novel, "Gabriel's Inferno," is #35 on the New York Times Bestsellers List, (Ebook/Fiction).

Similar to "Fifty Shades of Grey," the Gabriel's novels started life as a "Twilight" fan-fiction story called "The University of Edward Masen" posted on the web under the pen name Sebastien Robichaud at fan fiction sites like fanfiction.net and at sebastienrobichaud.com.

Reworked into Gabriel's Inferno, the first book was published by Omnific Publishing in April 2011. Together with its sequel, the books have consistently placed among the top 100 bestselling titles at Amazon.

The earlier "University of Edward Masen" version was taken offline and sebastienrobichaud.com was shut down.

The Hollywood Reporter describes the books:

"Gabriel's Inferno" and the sequel "Gabriel's Rapture" tells the story of Professor Gabriel Emerson, a Dante scholar who "uses his notorious good looks and sophisticated charm to gratify his every whim, but is secretly tortured by his dark past" and becomes romantically involved with his "sweet and innocent" graduate student. The romance "sends him on a journey in which his past and his present collide."

"Gabriel" readers might start asking about a movie deal soon, just like "Fifty Shades."