Like "Fifty Shades of Grey"? Try "Gabriel's Inferno"

(CBS News) A new series by an unknown author has scored a seven-figure book deal and is being described as the new "Fifty Shades of Grey."

Penguin's Berkley imprint says it has entered into a "substantial seven-figure deal" to buy Sylvain Reynard 's "Gabriel's Inferno" and "Gabriel's Rapture," according to the Hollywood Reporter.

Berkley will immediate take over publishing the ebooks from Omnific Publishing. Trade paperbacks will follow in early September, with Berkeley planning a 500,000-copy first printing.

Like "Fifty Shades," "Gabriel's Inferno" began life as "Twilight" fan fiction. It tells the story of a Dante scholar with a tortured past who becomes involved with an innocent graduate student. The author is thought to be Canadian but it's not know whether the writer is a man or a woman.

Dubbed "mommy porn," the erotic "Fifty Shades of Grey" and its two sequels have proved to be a publishing phenomenon. Vintage acquired the self-published books in March, and since then has sold more than 20 million copies of them. Focus Features recently paid the British author E.L. James $5 million for the film rights.